Opioid Antagonist

OPIOID ANTAGONIST

Q. 1 A 56-year-old man undergoes a  left upper lobectomy. An  epidural catheter is  inserted for postoperative pain relief. Ninety minutes after the first dose of epidural morphine, the patient complains of itching and becomes increasingly somnolent. Blood gas measurement reveals the following: pH 7.24; PaCO2 58; Pa02 100; HCO3:28 Initial therapy should include:
 A Endotracheal intubation
 B Intramuscular diphenhydramine 
 C Epidural naloxone
 D Intravenous naloxone
Q. 1 A 56-year-old man undergoes a  left upper lobectomy. An  epidural catheter is  inserted for postoperative pain relief. Ninety minutes after the first dose of epidural morphine, the patient complains of itching and becomes increasingly somnolent. Blood gas measurement reveals the following: pH 7.24; PaCO2 58; Pa02 100; HCO3:28 Initial therapy should include:
 A Endotracheal intubation
 B Intramuscular diphenhydramine 
 C Epidural naloxone
 D Intravenous naloxone
Ans. D

Explanation:

Intravenous naloxone

• Thoracic epidural narcotics have become an increasingly popular means of postoperative pain relief in thoracic and

upper abdominal surgery.

• Local action on gamma opiate receptors ensures pain relief and consequent improvement in respiration without vasodilation or paralysis.

• The less lipid-soluble opiates are effective for long periods.

• Their slow absorption into the circulation also ensures a low incidence of centrally mediated side effects, such as respiratory depression or generalized itching.

• When these do occur, the intravenous injection of an opiate antagonist is an effective antidote.

• The locally mediated analgesia is not affected.

• One poorly understood side effect, which is apparently unrelated to systemic levels,is a profound reduction in gastric activity. This may be an important consideration after thoracic surgery when an early resumption of oral intake is anticipated.

Narcotic Antagonist. naloxene  —

– Competes with narcotic at receptor sites.

– Dose 0.1-0.4mg IV.

– Half life is 20 minutes therefore naloxene may be given in an infusion eg. to reverse morphine or fentanyl which may have a second peak effect.


Q. 2

Which of the following is not a side effect ofnaloxone

 A >Seizure
 B >Hypertension
 C >Pulmonary edema
 D >Ventricular dysrrthymia
Q. 2

Which of the following is not a side effect ofnaloxone

 A >Seizure
 B >Hypertension
 C >Pulmonary edema
 D >Ventricular dysrrthymia
Ans. A

Explanation:

Seizure [Ref: Goodman Gilman 11/e p. 577, 578; KDT 6/e p. 466]

Opioid antagonists

  • Naloxone is an opioid antagonists
  • Under ordinary circumstances in normal individuals it does not produce any discernible effect.

–     It produces its effects only when agonistic opioids have been administered earlier to the patient.

– However, if endogenous opioid system is activated as in shock or certain forms of stress, the administration of opioid antagonist alone may have viable consequences.

  • Naloxone is an opioid antagonist and it promptly reverses the respiratory depressant property of opioids.
    – Other agnostic effects of opioids such as effects. on CNS and blood pressure is also reversed by opioids.

–      Naloxane is commonly used to reverse respiratory depression produced by opioid.

  • The antagonism of opioid effects by naloxone is often accompanied by “overshoot” phenomenon i.e.,while reversing the effect produced by the opioids it tends to overcorrect it.

– The respiratory rate depressed by opioids transiently become higher than that before the period of depression.

–     Rebound release of catecholamine may cause “hypertension”, “tachycardia” and “ventricular arrhythmias”. “Pulmonary edema” has also been reported after naloxone administration.

  • Naloxone may precipitate seizures but they are seen only in patients who are addicted to or dependent on opioids.

–      Small subcutaneous doses of naloxone precipitates a moderate to severe withdraw! syndrome that is very similar to that seen after abrupt withdrawl of opioids excepts that the syndrome appears within minutes of administration and subsides in about 2 hours.

–      However, seizure cannot be considered an adverse effect of naloxone.

Seizure occur as a part of withdrawl syndrome when naloxone is administered to those who are addicted or dependent on opioids.

When naloxone is administered in nonnal individuals to treat opioid overdose, it does not precipitate withdrawl syndrome and seizures do not occur.

–      On the other hand the cardiac effects i.e., arrhythmia, hyper- tension and pulmonary edema are produced when naloxone is administered in normal individual to reverse the effect of opioids.

–      These effects do not require the prior administration of opioids.


Q. 3

Naltrexone is used in opioid dependene to 

 A

Prevent respiratory depression

 B

Treat withdrawal symptoms

 C

Prevent relapse

 D

Treatment of opioid overdose

Q. 3

Naltrexone is used in opioid dependene to 

 A

Prevent respiratory depression

 B

Treat withdrawal symptoms

 C

Prevent relapse

 D

Treatment of opioid overdose

Ans. C

Explanation:

Prevent relapse [Ref: Harrison 17th/e p. 2732]

  • Naltrexone is a pure opioid antagonist
  • It is a competitive antagonist at all opioid receptors.
  • It can be used orally, to assist in the rehabilitation of ex-opioid abusers who are fully withdrawn (otherwise it will induce an acute withdraw! syndrome).
  • A patient who then takes an opioid, fails to experience the kick or euphoria because of the opioid antagonistic actions of the Naltrexone.

Quiz In Between


Q. 4

Naloxone is not used during resuscitation of a childwhose mother is on :

 A >Methadone
 B >Phenycyclidine
 C >Amphetamine
 D >Cocaine
Q. 4

Naloxone is not used during resuscitation of a childwhose mother is on :

 A >Methadone
 B >Phenycyclidine
 C >Amphetamine
 D >Cocaine
Ans. A

Explanation:

Metandone [Ref Goodman Gilman 10th/e p 603]

“At the delivery of known opioid dependent women, naloxone should be avoided in resuscitation of the infant because it may precipitate seizures”

  • Naloxone is used to reverse neonatal respiratory depression due to opioid use during labour.
  • It should not be used in cases where mother is opioid dependent. It can result in withdraw! syndrome.
  • When the mother is on opioids, fetus becomes opioid dependent in-utero and the use of naloxone in respiratory resuscitation may result in severe withdrawal symptoms.

According to Goodman Gilman

“In subjects who are dependent on morphine like opioids (methadone is pharmacologically similar to morphine) small subcutaneous doses of naloxone (5 mg) precipitate a moderate to severe withdraw! syndrome that is very similar to that seen after withdraw’ of opioids, except that the syndrome appears within minutes after administration and subsides in about 2 hours.”


Q. 5

The use of Naltrexone in opioid dependence is in which phase of treatment?

 A

Prevent respiratory depression

 B

To treat withdrawal symptom

 C

To prevent relapse

 D

To treat overdose of opioid

Q. 5

The use of Naltrexone in opioid dependence is in which phase of treatment?

 A

Prevent respiratory depression

 B

To treat withdrawal symptom

 C

To prevent relapse

 D

To treat overdose of opioid

Ans. C

Explanation:

Naltrexone is a long acting opioid antagonist.
It is used in patients of opioid dependence for detoxification and withdrawal.
It discourages substance seeking behaviour and thus prevents relapse.
It can cause withdrawal symptoms in addicts due to blockage of opioid receptors.
 
Ref: Kaplan & Sadock Synopsis of Psychiatry 9th Edition, Page 1082-87, 448-456; A short textbook of Psychiatry by Neraj Ahuja 5th Edition, Page 45-48; Essentials of Pharmacology by K D Tripathi 5th Edition, Page 425; Shorter Oxford Textbook of Psychiatry 5th Edition, Page 358-361

Q. 6

Naltrexone is used in opioid dependence to:

 A

Prevent respiratory depression

 B

Treat withdrawal symptoms

 C

Prevent relapse

 D

Treatment of opioid overdose

Q. 6

Naltrexone is used in opioid dependence to:

 A

Prevent respiratory depression

 B

Treat withdrawal symptoms

 C

Prevent relapse

 D

Treatment of opioid overdose

Ans. C

Explanation:

Naltrexone a long acting opioid antagonist competitively block the opioid receptor and blocks the effects of opioids.
Regular dosing of naltrexone prevents patients from experiencing the effect of opioids thereby preventing relapse.
 
Opioid antagonists are used in the treatment of opioid dependence in 3 ways:
  • To reverse an opioid overdose
  • To prevent relapse by blocking opioids from producing their effect at opioid receptors
  • To identify those with opioid dependence by inducing withdrawal symptoms to provide evidence of opioid dependence.
Ref: Cambridge Textbook of Effective Treatments in Psychiatry  by Peter Tyrer, Page 386

Quiz In Between


Q. 7

What is the mechanism of action of use of Naltrexone in alchohol addiction in a 45-year-old man?

 A

Inhibits metabolism of alcohol

 B

Blocks opioid receptors

 C

Affects GABA neurotransmitter system

 D

None of the above

Q. 7

What is the mechanism of action of use of Naltrexone in alchohol addiction in a 45-year-old man?

 A

Inhibits metabolism of alcohol

 B

Blocks opioid receptors

 C

Affects GABA neurotransmitter system

 D

None of the above

Ans. B

Explanation:

Naltrexone blocks opioid receptors and reduces craving for alcohol and opioids.

It also reduces reward in response to drinking. Hence it is useful to prevent relapse in a de-addiction programme. 

Inhibits metabolism of alcohol: Disulfiran inhibits metabolish of alcohol and leads to accumulation of acetaldehyde. 

Affects GABA neurotransmitter system: Acamprosate affects GABA and Glutamate neurotransmitter system.

Ref: Kaplan & Sadock’s Synopsis of Psychiatry, By Benjamin J Sadock, M.D., Harold I. Kaplan, Virginia A Sadock, M.D, 10th Edition, Page : 406


Q. 8

Which of the following drug is used for long term maintenance in opioid addiction?

 A

Naloxone

 B

Naloxone

 C

Butylphenol

 D

Methadone

Q. 8

Which of the following drug is used for long term maintenance in opioid addiction?

 A

Naloxone

 B

Naloxone

 C

Butylphenol

 D

Methadone

Ans. D

Explanation:

 Methadone has a long half life of 15-40 hours.
Because of the extended duration of action it suppresses the withdrawal symptoms in dependent patients and is therefore used for long term maintenance in opioid addiction.
 
Methadone is a slow-acting agonist of -opioid receptor.
It is absorbed well from the GI tract and can be detected in plasma within 30 minutes of oral ingestion.
 Peak concentrations occur in brain within 1-2 hours of subcutaneous or intramuscular administration. 
 
It is primarily used  for the relief of chronic pain, in the treatment of opioid abstinence syndromes, and for treating heroin users. Methadone causes prolongation of QT interval. It causes serious cardiac arrhythmias including torsade de pointes. 
 
Ref: Yaksh T.L., Wallace M.S. (2011). Chapter 18. Opioids, Analgesia, and Pain Management.

Q. 9

Naloxone for opioid receptor acts as:

 A

Pure agonist

 B

Pure antagonist

 C

Partial agonist

 D

Agonist antagonist

Q. 9

Naloxone for opioid receptor acts as:

 A

Pure agonist

 B

Pure antagonist

 C

Partial agonist

 D

Agonist antagonist

Ans. B

Explanation:

Naloxone is a pure antagonist and is preferred over older weak agonist-antagonist agents that had been used primarily as antagonists, eg, nalorphine and levallorphan.
 
Ref: Katzung, 11th edition, Chapter 31.

Quiz In Between


Q. 10

A 32 year old woman, gravida 4, para 3, at 39 weeks gestation comes the labor and delivery ward with painful contractions. Her prenatal course was unremarkable. Examination shows that her cervix is 5 cm dilated, 100% effaced and the fetal heart rate is in the 130s and reactive. She is given meperidine for pain control. She progresses rapidly and less than 2 hours later she delivers a 3.345Kg male fetus. The one-minute APGAR score is 1 and the infant is making little respiratory effort. Which of the following is the most appropriate next step in management?

 A

Blood transfusion

 B

Glucose

 C

Naloxone

 D

Sodium bicarbonate

Q. 10

A 32 year old woman, gravida 4, para 3, at 39 weeks gestation comes the labor and delivery ward with painful contractions. Her prenatal course was unremarkable. Examination shows that her cervix is 5 cm dilated, 100% effaced and the fetal heart rate is in the 130s and reactive. She is given meperidine for pain control. She progresses rapidly and less than 2 hours later she delivers a 3.345Kg male fetus. The one-minute APGAR score is 1 and the infant is making little respiratory effort. Which of the following is the most appropriate next step in management?

 A

Blood transfusion

 B

Glucose

 C

Naloxone

 D

Sodium bicarbonate

Ans. C

Explanation:

Meperidine can be used as a systemic analgesia during labor.

It is an opioid and readily crosses the placenta; therefore, the fetus is exposed to the medication.

As an opioid, it causes respiratory depression.

Neonates are at greatest risk for respiratory depression when delivery occurs approximately 2 to 3 hours after meperidine is administered to the mother. This neonate was born approximately 2 hours after maternal administration of meperidine, which makes neonatal respiratory depression likely. Naloxone is a pure opioid antagonist that displaces the opioid from its receptor sites and can help to reverse the opioid- induced respiratory depression. It has a short duration of action so repeat doses may be necessary.

Blood transfusion would not be indicated. Blood transfusions are used when there is evidence that the neonate is anemic. This neonate appears to have respiratory depression and not anemia. Therefore, naloxone, and not blood transfusion, would be indicated.

Glucose should be given when there is evidence that the neonate is severely hypoglycemic. This neonate, given that its mother received an opioid 2 hours ago, is most likely to have respiratory depression from the opioid and not hypoglycemia.

Sodium bicarbonate should be given to a neonate for documented metabolic acidosis. It is often used during a prolonged resuscitation. The first step for this neonate, however, would be to try to reverse the respiratory depression with naloxone.
 
Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 19. Obstetrical Anesthesia. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.


Q. 11

Treatment of opiod dependence includes: 

 A

Naloxone

 B

Naltrexone

 C

Acamprostate

 D

All

Q. 11

Treatment of opiod dependence includes: 

 A

Naloxone

 B

Naltrexone

 C

Acamprostate

 D

All

Ans. B

Explanation:

B i.e. Naltrexone

Management of Opioid related Disorders

–  Opiate (eg heroin) toxicity and overdose

(intoxication) management requires IM/IV naloxone (drug of choice)Q, or nalmefene, support of vital functions (02, positive pressure breathing, IV fluids, pressor agents for hypotension & cardiac monitoring for QT prolongation) and intubation (±).

In opioid dependent (& intoxicated) patients administration of opioid antagonists (eg naloxone & nalmefene; both approved for overdose/intoxication) may produce signs of opioid withdrawl (precipitated opioid withdrawl) as well as reversal of overdose. A relative advantage of naloxone is that withdrawl effects are of short duration (ti/2 = 60-90 min) in comparison to nalmefene (t1/2 = 10 hours)

 

Opioid related disorder

Drugs Used

Overdose/Intoxication

Naloxone (1st), Nalmefene (2nd)Q

Withdrawl Symptoms

Methadone (1st), Buprenorphine

(symptomatic relief)

(2nd), LAAM (no longer used),

Clonidine/ Lofexidine (3rd),

Benzodiazepines & Tramadol

Withdrawl Treatment

All above + Naltrexone (for rapid

(Detoxification)

detoxifiation; however it can’t be

used alone)

Opioid Dependence

Methadone , Buprenorphine,

(Maintenance

LAAM (no longer used /

treatment)

available / recommended),

Naltrexone (to prevent relapseQ)

Opioid withdrawl syndrome (symptoms) can be treated by weak or partial opioid agonist such as methadone (drug of 1″ choice)Q, buprenorphine (drug of 2″ choice)Q, LAAM (not recommended as it prolongs QT interval) and a2 adrenergic agonist drugs such as clonidine (drug of 3rd choice)Q and lofexidineQ (clonidine analogue with less hypotensive effect). Weak or partial opioid agonists act by stabilizing the patient on an equivalent drug with less addition/abuse potential, and then the substituted drug is gradually withdrawn. Whereas, a-2 adrenergic agonist drugs are centrally acting sympatholytic agents with no addiction and no narcotic action and relieve opioid withdrawl symptoms by reducing central sympathetic outflow (noradrenergic hyperactivity).

Opiate withdrawl treatment (or detoxification) is done by methadone (1st choice), buprenorphine (2nd), LAAM (not recommended), clonidine (3rd) and lofexidineQ. Opioid antagonist naltrexone combined with az adrenergic agonist is used to shorten the duration of withdrawl with out significantly increasing patient discomfort (i.e. rapid & ultra rapid opiate detoxification = ROD). Another benefit of ROD is reduced time between opioid use and commencement of sustained naltrexone treatment for prevention of relapseQ. Ultrarapid opiate detoxification is an extension of ROD using anesthetics.

Alpha 2 adrenergic agonists are primarily used for detoxification (treatment of withdrawl symptoms). Weak agonist and partial opioid agonist medications are commonly used for detoxifiation (treatment of withdrawl symptoms) and maintenance treatment for opioid dependence. Opioid antagonists (eg naltrexone) are used to accelerate detoxification (used in withdrawl treatment but does not treat withdrawl symptoms) and then continued post detoxification to prevent relapseQ. Opioid antagonist naltrexone must be started after detoxification or with a2 agonist, to prevent withdrawl symptoms.

For opioid dependence (chronic use), FDA approved maintenance treatment include opioid agonists methadone, buprenorphinQ and LAAM (not preferred; but theoritically can be given) and opioid antagonist naltrexoneQ.

Cognitive behavior therapy, psychodynamic & interpersonal therapies, self help and 12-step group therapy, behavioral therapies and therapeutic communities help to achieve opioid abstinence.


Q. 12

Naltrexone is used in opioid addiction because

 A

To treat withdrawal symptoms

 B

To treat overdose of opioids and present respiratory

depression

 C

Prevent relapse

 D

Has addiction potential; used for detoxification of opioid

Q. 12

Naltrexone is used in opioid addiction because

 A

To treat withdrawal symptoms

 B

To treat overdose of opioids and present respiratory

depression

 C

Prevent relapse

 D

Has addiction potential; used for detoxification of opioid

Ans. C

Explanation:

C i.e. Prevent relapse

Quiz In Between


Q. 13

The drug which is used for long term maintenance in opioid addiction:

 A

Naloxone

 B

Nalorphine

 C

Butarphamol

 D

Methadione

Q. 13

The drug which is used for long term maintenance in opioid addiction:

 A

Naloxone

 B

Nalorphine

 C

Butarphamol

 D

Methadione

Ans. D

Explanation:

D i.e. Methadone 

Naloxone is used in opioid overdoseQ and ultrarapid detoxification of opioid dependent (addicts)Q. Due to short duration of action (t1/2 = 1-2 hour), frequent dosing is required, which makes it unsuitable for maintenance treatmentQ. Naltrexone & Nalmefene are used in rapid detoxification and maintenance of ultrarapid detoxification in opioid addicts (dependent). And methadone is used in short term detoxification, long term detoxification & long term maintenance in opioid dependant (addicts)Q. 


Q. 14

In patients of substance-abuse, drugs used are: 

 A

Naltrexone

 B

Naloxone

 C

Clonidine

 D

All

Q. 14

In patients of substance-abuse, drugs used are: 

 A

Naltrexone

 B

Naloxone

 C

Clonidine

 D

All

Ans. D

Explanation:

A i.e. Naltrexone; B i.e. Naloxone; C i.e. Clonidine


Q. 15

A 34-year old rickshaw puller has been using heroin for the past ten years. One evening his family members found him unconscious. He was brought to the casualty. On examination he had tachycardia, shallow breathing, constricted pupils. His blood pressure was 100/70 mm of Hg. He had brisk bilateral deep tendon reflexes. The planter reflexes were flexor on both sides. Which of the following is the best treatment for him?

 A

Buprenorphine

 B

Flumazenil

 C

Methadone

 D

Naloxone

Q. 15

A 34-year old rickshaw puller has been using heroin for the past ten years. One evening his family members found him unconscious. He was brought to the casualty. On examination he had tachycardia, shallow breathing, constricted pupils. His blood pressure was 100/70 mm of Hg. He had brisk bilateral deep tendon reflexes. The planter reflexes were flexor on both sides. Which of the following is the best treatment for him?

 A

Buprenorphine

 B

Flumazenil

 C

Methadone

 D

Naloxone

Ans. D

Explanation:

D i.e. Naloxone

In this case you have to diagnose first that whether this is a case of opoid intoxication or withdrawl, and which can be easily done by seeing pupils.

Quiz In Between


Q. 16

Not true about Naltrexone

 A

Parenterally administered

 B

Used to prevent relapse of heavy drinking

 C

Long acting

 D

Cause hepatotoxicity

Q. 16

Not true about Naltrexone

 A

Parenterally administered

 B

Used to prevent relapse of heavy drinking

 C

Long acting

 D

Cause hepatotoxicity

Ans. A

Explanation:

Ans. is ‘a’ i.e., Parenterally administered

Naltrexone (antagonist on all opioid receptors)

o More potent than naloxone.

  • It can be given orally
  • It is used as a maintenance drug for opioid addicts – opioid blockade therapy ofpostaddict.

o It is also used to decrease craving in chronic alcoholism.

o The most important side effect is hepatotoxicity.


Q. 17

Naltrexone is used to maintain abstinence following opioid withdrawal in addicts. It blocks all of the following featues of opioid use, except – 

 A

Euphoriant effects of opioids

 B

Craving for opioids

 C

Miosis

 D

Respiratory depression

Q. 17

Naltrexone is used to maintain abstinence following opioid withdrawal in addicts. It blocks all of the following featues of opioid use, except – 

 A

Euphoriant effects of opioids

 B

Craving for opioids

 C

Miosis

 D

Respiratory depression

Ans. B

Explanation:

Ans. is ‘b’ i.e., Craving for opioids

o Naltrexone can reverse all effects of opioids like sedation, analgesia, constipation, respiratory depression and miosis, but it does not reduce craving.

“Craving for opioids may continue during naltrexone treatment” Principles of addiction medicine

o It is interesting to know that naltrexone does not reduce craving for opioid, but it reduces craving for alcohol in chronic alcoholism


Q. 18

Opioid Specific antagonist is –

 A

Naloxone

 B

Naltrexone

 C

Methadone

 D

a and b

Q. 18

Opioid Specific antagonist is –

 A

Naloxone

 B

Naltrexone

 C

Methadone

 D

a and b

Ans. D

Explanation:

Ans. is ‘a’ i.e., Naloxone; ‘b’ i.e., Naltrexone

Naloxone (antagonist on all opioid receptors)

o It antagonizes all action of morphine (sedation is less completely reversed).

o It is the drug of choice for acute morphine poisoning.

o It is also used for reversing neonatal asphyxia due to opioid use during labour, alcohol intoxication and to elevate BP in endotoxic or hypovolaemic shock.

o It precipitates withdrawl in dependent subjects —> can be used for diagnosis of opioid dependence.

o It partly antagonizes respiratory depression produced by certain nonopioid also, e.g. NCO, diazepam. o It is ineffective orally because of high first pass metabolism – used parenterally.

o It is very short acting (t’ = 1 hour in adults and 3 hours in newborns)

Nalnefene (antagonist on all opioid receptors)

o Has high oral bioavailability but it is used i.v.,.

o Lacks hepatotoxicity of naltrexone.

o It is longer acting.

o It is used in alcohol dependence.

Naltrexone:  It is also an opioid specific antagonist (see previous explanations)

Quiz In Between


Q. 19

Which of the following statements about opioid receptor antagonists is false –

 A

Naloxone can be used for treatment of opioid induced constipation

 B

Naltrexone may be used for treatment of alcohol dependence

 C

Nalmefine has a longer half life than naloxone

 D

Naloxone is more potent than naltrexone

Q. 19

Which of the following statements about opioid receptor antagonists is false –

 A

Naloxone can be used for treatment of opioid induced constipation

 B

Naltrexone may be used for treatment of alcohol dependence

 C

Nalmefine has a longer half life than naloxone

 D

Naloxone is more potent than naltrexone

Ans. D

Explanation:

Ans. is ‘d’ i.e., Naloxone is more potent than naltrexone

o Naltrexone is more potent than naloxone. Naltrexone has 3 to 5 times more potency than naloxone.

o Opioid induced constipation that is refractory to laxative may be treated with oral naloxone. Oral naloxone can reverse opioid induced constipation without precipitating withdrawal because of its extensive hepatic first pass metabolism, which leads to low plasma level.

o Naltrexone is used to decrease craving in chronic alcoholism.


Q. 20

Naltrexone is used for which of the following poisoning –

 A

Heroin

 B

Atropine

 C

Cannabis

 D

Diazepam

Q. 20

Naltrexone is used for which of the following poisoning –

 A

Heroin

 B

Atropine

 C

Cannabis

 D

Diazepam

Ans. A

Explanation:

Ans. is ‘a’ i.e., Heroin

o Naltrexone is used in opioid poisoning and amongst the given options only heroin is an opioid.

o Naltrexone is used orally for maintenance therapy in opioid poisoning, once it has been treated with naloxone.

So,

Naloxone : DOC for acute opioid (morphine) poisoning Naltrexone : Used for maintenance


Q. 21

Which of the following drugs does not possess even slightest agonist action ?

 A

Buprenorphine

 B

Butorphanol

 C

Nalbuphine

 D

Nalmefene

Q. 21

Which of the following drugs does not possess even slightest agonist action ?

 A

Buprenorphine

 B

Butorphanol

 C

Nalbuphine

 D

Nalmefene

Ans. D

Explanation:

Ans. is `d’ i.e., Nalmefene

Nalmefene is pure antagonist.

Quiz In Between


Q. 22

Naloxone is not used during resuscitation of a child whose mother is on –

 A

Methadone

 B

Phenylcyclidine

 C

Amphetamine

 D

Cocain

Q. 22

Naloxone is not used during resuscitation of a child whose mother is on –

 A

Methadone

 B

Phenylcyclidine

 C

Amphetamine

 D

Cocain

Ans. A

Explanation:

Ans. is ‘a’ i.e., Methadone

o Naloxone is used to reverse neonatal respiratory depression due to opioid use during labour.

o It should not be used in cases where mother is opioid dependent. It can result in withdraw! syndrome.

o When the mother is on opioids, fetus becomes opioid dependent in-utero and the use of naloxone in respiratory resuscitation may result in severe withdraw! symptoms.

“In subjects who are dependent on morphine like opioids (e.g. methadone) small cutaneous doses of naloxone precipitate a moderate to severe withdrawl syndrome that is very similar to that seen after withdrawl of opioids, except that syndrome appears within minutes after administration and subsides in about 2 hours”.


Q. 23

Which of the following is used to maintain abstinence in alcohol dependence ?

 A

Naltrexone

 B

Clonidine

 C

Disulfiram

 D

Naloxone

Q. 23

Which of the following is used to maintain abstinence in alcohol dependence ?

 A

Naltrexone

 B

Clonidine

 C

Disulfiram

 D

Naloxone

Ans. A

Explanation:

Ans. is ‘a’ i.e., Naltrexone

o Naltrexone is the preferred agent for maintaince of abstinence in alcohol dependence.


Q. 24

All are opioid agonist – antagonist compounds except

 A

Buprenorphine

 B

Nalbuphine

 C

Pentazocine

 D

Nalmefene

Q. 24

All are opioid agonist – antagonist compounds except

 A

Buprenorphine

 B

Nalbuphine

 C

Pentazocine

 D

Nalmefene

Ans. D

Explanation:

D i.e. Nalmefene

Quiz In Between


Q. 25

Best antagonist of morphine is

 A

Nalorphine

 B

Naloxone

 C

Buprenorphine

 D

Pentazocine

Q. 25

Best antagonist of morphine is

 A

Nalorphine

 B

Naloxone

 C

Buprenorphine

 D

Pentazocine

Ans. B

Explanation:

B i.e. Naloxone


Q. 26

Naltrexone is:   

March 2013

 A

(mu) agonist

 B

6 (delta) agonist

 C

lc (kappa) antagonist

 D

NOP receptor antagonist

Q. 26

Naltrexone is:   

March 2013

 A

(mu) agonist

 B

6 (delta) agonist

 C

lc (kappa) antagonist

 D

NOP receptor antagonist

Ans. C

Explanation:

Ans. C i.e. lc antagonist

Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence.


Q. 27

The drug which is used in long term maintenance in opioids addiction:          

March 2013 (h)

 A

Naloxone

 B

Nalorphine

 C

Butarphanol

 D

Methadone

Q. 27

The drug which is used in long term maintenance in opioids addiction:          

March 2013 (h)

 A

Naloxone

 B

Nalorphine

 C

Butarphanol

 D

Methadone

Ans. D

Explanation:

Ans. D i.e. Methadone

Drugs in psychiatry

Naltrexone:

– Used in opioid dependency:

  • For rapid detoxification
  • Maintenance therapy

–  To prevent relapse

Tolpromate:

–  Used to reduce craving and

– Prevent relapse in heavy alcohol drinking (alcohol dependence)

Lithium:

– Therapeutic serum level is 0.6-1.2 mmol/L,

– Liver is NOT affected in lithium toxicity,
ECG changes of lithium toxicity are:

  • Sinus tachycardia/ bradycardia,
  • Flattened/inverted T waves,
  • AV block and
  • A prolonged QT interval,

–  Lithium is C/ I in pregnancy (causes CVS defects)

Drugs used in Maniac Depressive Psychosis/MDP:

– Lithium,

– Valproate,

– Carbamazepine,

– Levothyroxine

  • Agent of choice for prophylaxis in mania: Lithium (mood stabilizer)

Drug causing depression:

– OCP,

– Bromocriptine etc.

TCA:

– Amitryptiline,

– Clomipramine etc.

Tetracyclic antidepressant:

– Maprotiline,

– Mianserin etc.

SSRI:

–  Fluoxetine,

–  Fluoxamine etc.

Quiz In Between


Q. 28

Opium poisoning is treated with:

MAHE 06; Bihar 12; UPSC 13

 A

Naloxone

 B

Atropine

 C

Neostigmine

 D

Physostigmine

Q. 28

Opium poisoning is treated with:

MAHE 06; Bihar 12; UPSC 13

 A

Naloxone

 B

Atropine

 C

Neostigmine

 D

Physostigmine

Ans. A

Explanation:

Ans. Naloxone


Q. 29

Naltrexone is used in:     

Bihar 10; AIIMS 10

 A

Treat withdrawal symptoms

 B

Treatment of overdose

 C

Prevention of relapse

 D

a and b

Q. 29

Naltrexone is used in:     

Bihar 10; AIIMS 10

 A

Treat withdrawal symptoms

 B

Treatment of overdose

 C

Prevention of relapse

 D

a and b

Ans. D

Explanation:

Ans. a and b


Q. 30

The drug which is used for long-term maintenance in opioid addiction:           

AIIMS 06; Punjab 09; AI 11

 A

Nalorphine

 B

Naloxone

 C

Butarphanol

 D

Methadone

Q. 30

The drug which is used for long-term maintenance in opioid addiction:           

AIIMS 06; Punjab 09; AI 11

 A

Nalorphine

 B

Naloxone

 C

Butarphanol

 D

Methadone

Ans. D

Explanation:

Ans. Methadone

Quiz In Between


Q. 31

All are used in nicotine de-addiction, except:

NIMHANS 10, 11

 A

Bupropion

 B

Clonidine

 C

Nicotine gum

 D

Buspirone

Q. 31

All are used in nicotine de-addiction, except:

NIMHANS 10, 11

 A

Bupropion

 B

Clonidine

 C

Nicotine gum

 D

Buspirone

Ans. D

Explanation:

Ans. Buspirone


Q. 32

Drugs for paralytic ileus for bowel resection surgery are all except ‑

 A

Alvinopam

 B

Dihydroergotamine

 C

Naloxone

 D

Methylnaltrexone

Q. 32

Drugs for paralytic ileus for bowel resection surgery are all except ‑

 A

Alvinopam

 B

Dihydroergotamine

 C

Naloxone

 D

Methylnaltrexone

Ans. C

Explanation:

Ans. is ‘c’ i.e., Naloxone

Pharmacologic Management of Post op paralytic ileus (P01):

  • Minimizing the sympathetic inhibition of gastrointestinal motility, decreasing inflammation and stimulation of gastrointestinal 11-opioid receptors are the ultimate goals of pharmacologic management.

A) Minimizing sympathetic inhibition

  • Both propranolol, a nonspecific 13-receptor antagonist, and dihydroergotamine, an a-receptor antagonist, have been investigated for treatment of POI.
  • Neostigmine is an acetylcholinsterase inhibitor that causes an increase in cholinergic (parasympathetic) activity in the gut wall, which is believed to thereby stimulate colonic motility.
  • Use of edrophonium chloride and bethanechol chloride, which competitively inhibit acetylcholine on the binding site of acetylcholinesterase, has been reported to show improvement of POI.
  • Cisapride is a serotonin (5-HT)4 receptor antagonist that promotes acetylcholine release from postganglionic nerve endings in the myenteric plexus and is thought to indirectly improve gastrointestinal motility.
  • Metocloprimide is suspected to enhance gastrointestinal motility without stimulating gastric secretion, but its use has not been substantiated for POI.

B) Decreasing inflammation

  • Decreasing inflammation may be indicated in patients who are about to undergo major intestinal surgery, as this is thought to be an important contributing factor to POI.
  • Nonsteroidal anti-inflammatory (NSAIDs) agents can be used in conjunction with opioid analgesics for their dual effects on pain control and inflammatory inhibition.

C) Stimulation of gastrointestinal iii-opioid receptors

  • Stimulation of gastrointestinal .1-opioid receptors can theoretically influence gastrointestinal motility directly; therefore, blocking the peripheral gastrointestinal effects of centrally acting opioids used for analgesia may help prevent POI.
  • Two novel drugs are being investigated for this reason: alvimopan and methylnaltrexone.
  • Both drugs are If-opioid receptor antagonists, and both appear to offer promising results for preventing prolonged POI.
  • Opioid therapy for postoperative or chronic pain is frequently associated with adverse effects, the most common being dose-limiting and debilitating bowel dysfunction, so alvimopan and methylnaltrexone may also be useful in the treatment of chronic opioid bowel dysfunction.
  • The currently available opioid antagonists such as naloxone are of limited use because they also act at central opioid receptors to reverse analgesia and elicit opioid withdrawal.
  • Alvimopan and methylnaltrexone are peripherally acting if-opioid receptor antagonists that have been studied in patients undergoing abdominal and pelvic surgery and have been shown in several studies to significantly accelerate gastrointestinal recovery. Alvimopan received FDA approval for the treatment of POI on May 20, 2008.

D) Alternative medications

  • Bisacodyl administration versus placebo twice daily starting on postoperative day 1, patients who received bisacodyl had significantly earlier bowel movements than those who received placebo (25 h v. 56 h), but further studies are needed to assess the effect of laxatives on POI.

Q. 33

Transdermal patch is not used for following drug‑

 A

GTN

 B

Fentanyl

 C

Nicotine

 D

Naloxone

Q. 33

Transdermal patch is not used for following drug‑

 A

GTN

 B

Fentanyl

 C

Nicotine

 D

Naloxone

Ans. D

Explanation:

Ans. is `d’ i.e., Naloxone

Quiz In Between


Q. 34

Antidote true is all except‑

 A

Deferoxamine – Iron

 B

Flumazenil – BZDs

 C

Dimercaprol – Arsenic

 D

Naloxone – Dhatura

Q. 34

Antidote true is all except‑

 A

Deferoxamine – Iron

 B

Flumazenil – BZDs

 C

Dimercaprol – Arsenic

 D

Naloxone – Dhatura

Ans. D

Explanation:

Ans. is ‘d’ i.e., Naloxone-Dhatura


Q. 35

The drug of choice for poisoning due to substance shown in Photograph is ? 

 A

Pyridoxine.

 B

N-acetylcysteine.

 C

Prazosin.

 D

Naloxone.

Q. 35

The drug of choice for poisoning due to substance shown in Photograph is ? 

 A

Pyridoxine.

 B

N-acetylcysteine.

 C

Prazosin.

 D

Naloxone.

Ans. D

Explanation:

Naloxone blocks or reverses the effects of opioid medication, including extreme drowsiness, slowed breathing, or loss of consciousness. An opioid is sometimes called a narcotic.

Naloxone is used to treat a narcotic overdose in an emergency situation. This medicine should not be used in place of emergency medical care for an overdose.

Naloxone is also used to help diagnose whether a person has used an overdose of an opioid.


Q. 36

Drug used in neonatal resuscitation

 A

Adrenaline

 B

Soda bi carbonate

 C

Naloxone

 D

All of above

Q. 36

Drug used in neonatal resuscitation

 A

Adrenaline

 B

Soda bi carbonate

 C

Naloxone

 D

All of above

Ans. D

Explanation:

Ans. is ‘d’ i.e., All of above

Drug used during neonatal resuscitation

  • Epinephrine./Adrenalin
  • NS or RL
  • Naloxone
  • Sodium-by-carbonate

Q. 37

The following agent decrease gastric motility except

 A

Naloxone

 B

Morphine

 C

Codeine

 D

Pethidine

Q. 37

The following agent decrease gastric motility except

 A

Naloxone

 B

Morphine

 C

Codeine

 D

Pethidine

Ans. A

Explanation:

Ans. is ‘a’ i.e., Naloxone

  • Opioids decrease GI motility.
  • Naloxone is opioid antagonist (at all receptors), thus it will counteract the GI effect of opioids.

Naloxone

  • It antagonizes all action of morphine (sedation is less completely reversed).
  • It is the drug of choice for acute morphine poisoning.
  • It is also used for reversing neonatal asphyxia due to opioid use during labour, alcohol intoxication and to elevate BP in endotoxic or hypovolaemic shock.
  • It precipitates withdrawl in dependent subjects → can be used for diagnosis of opioid dependence.
  • It partly antagonizes respiratory depression produced by certain nonopioid also, e.g. N20, diazepam. 
  • It is ineffective orally because of high first pass metabolism – used parenterally.
  • It is very short acting (t”2 1 hour in adults and 3 hours in newborns).

Quiz In Between



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