A 52-year-old woman has taken lithium for 10 years. After 4 days of vomiting and diarrhoea she is brought to casualty confused, with a coarse tremor, ataxia and myoclonic jerks. Serum lithium is 4.6 mEq/L (therapeutic 0.6-1.0), creatinine 2.8 mg/dL (baseline 0.9 mg/dL) and sodium 134 mmol/L. IV normal saline has been started. What is the next best step?

Alkaline diuresis with sodium bicarbonate

Activated charcoal by nasogastric tube

IV furosemide to increase excretion

A 30-year-old woman with epilepsy had her sodium valproate dose increased 3 weeks ago. She is now drowsy, confused and vomiting, with no seizures. Valproate level is 85 µg/mL (therapeutic 50-100), ALT 32 U/L, bilirubin 0.8 mg/dL, INR 1.0 and glucose 96 mg/dL. Plasma ammonia is 160 µmol/L (reference below 50). What is the next best step?

Stop valproate and give L-carnitine

Continue valproate and give thiamine

Start N-acetylcysteine for liver injury

Continue valproate and add lactulose

Antiepileptics, antidepressants, antipsychotics and anti-Parkinson drugs

23 NEET-PG practice questions on Antiepileptics, antidepressants, antipsychotics and anti-Parkinson drugs, part of Pharmacology. The first 23 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 19-year-old college student has myoclonic jerks of the arms soon after waking, worse after late nights, and had one generalised tonic-clonic seizure last week. EEG shows generalised polyspike-and-wave discharges. She may want children in a few years. Which drug is the best first choice for her?
1. ACarbamazepine
2. BPhenytoin
3. CLevetiracetam
4. DSodium valproate
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Answer: C · Levetiracetam
This is juvenile myoclonic epilepsy, which needs a broad-spectrum antiseizure drug, usually for life. Valproate works well but is strongly teratogenic (neural tube defects, lower childhood IQ), so current guidance avoids it in girls and women who could become pregnant. Levetiracetam controls myoclonic and generalised seizures and is relatively safe in pregnancy. She should be counselled about sleep and alcohol, folic acid, and planning any pregnancy with her doctor.
- A: Carbamazepine can worsen myoclonic seizures.
- B: Phenytoin can worsen myoclonic seizures and has many adverse effects.
- D: Valproate is effective but avoided in women of childbearing potential because of teratogenicity.
Question 2 · Hard
A 52-year-old woman has taken lithium for 10 years. After 4 days of vomiting and diarrhoea she is brought to casualty confused, with a coarse tremor, ataxia and myoclonic jerks. Serum lithium is 4.6 mEq/L (therapeutic 0.6-1.0), creatinine 2.8 mg/dL (baseline 0.9 mg/dL) and sodium 134 mmol/L. IV normal saline has been started. What is the next best step?
1. AAlkaline diuresis with sodium bicarbonate
2. BHaemodialysis
3. CActivated charcoal by nasogastric tube
4. DIV furosemide to increase excretion
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Answer: B · Haemodialysis
Volume loss from gastroenteritis cut her lithium clearance and caused chronic toxicity, and the kidney injury will keep the level high. Lithium is a small, water-soluble ion that is not protein bound, so haemodialysis removes it well; it is indicated here because of neurological toxicity with a very high level and impaired kidney function. Levels often rebound after dialysis as lithium leaves the tissues, so they are rechecked and dialysis repeated if needed. Chronic toxicity can leave permanent cerebellar damage.
- A: Alkaline diuresis does not increase lithium clearance and adds a sodium load.
- C: Activated charcoal does not bind lithium.
- D: Loop diuretics worsen volume depletion and lithium retention.
Question 3 · Hard
A 30-year-old woman with epilepsy had her sodium valproate dose increased 3 weeks ago. She is now drowsy, confused and vomiting, with no seizures. Valproate level is 85 µg/mL (therapeutic 50-100), ALT 32 U/L, bilirubin 0.8 mg/dL, INR 1.0 and glucose 96 mg/dL. Plasma ammonia is 160 µmol/L (reference below 50). What is the next best step?
1. AContinue valproate and give thiamine
2. BStart N-acetylcysteine for liver injury
3. CContinue valproate and add lactulose
4. DStop valproate and give L-carnitine
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Answer: D · Stop valproate and give L-carnitine
Confusion with a high ammonia but normal liver tests and a normal drug level is valproate-induced hyperammonaemic encephalopathy. Valproate metabolites impair the urea cycle by reducing activation of carbamoyl phosphate synthetase I, and valproate depletes carnitine. The drug is stopped and L-carnitine given; a different antiepileptic is then chosen. This differs from valproate hepatotoxicity, which raises transaminases and INR and mostly affects young children on several drugs.
- A: Thiamine treats Wernicke encephalopathy, which does not cause high ammonia.
- B: N-acetylcysteine is for paracetamol-type liver injury; her liver tests are normal.
- C: Lactulose alone leaves the cause running; valproate must be stopped.
Question 4 · Medium
A 70-year-old woman with Parkinson disease is started on levodopa-carbidopa and develops nausea and vomiting after each dose. Which antiemetic is preferred?
1. AMetoclopramide
2. BProchlorperazine
3. CLevosulpiride
4. DDomperidone
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Answer: D · Domperidone
Domperidone blocks D2 receptors in the chemoreceptor trigger zone, which lies outside the blood-brain barrier, but crosses into the brain very little. It therefore relieves dopamine-induced nausea without worsening parkinsonism or blocking the action of levodopa in the striatum. It can prolong the QT interval, so the lowest effective dose is used. Metoclopramide, prochlorperazine and levosulpiride all enter the brain and can worsen parkinsonism.
- A: Metoclopramide crosses the blood-brain barrier and worsens parkinsonism.
- B: Prochlorperazine is a phenothiazine that blocks striatal D2 receptors.
- C: Levosulpiride, widely used in India, is a central D2 blocker that causes parkinsonism.
Question 5 · Medium
A 7-month-old boy from Bihar has clusters of sudden flexion of the trunk and arms on waking, and he has lost the ability to sit. He has three hypopigmented ash-leaf macules on the trunk. EEG shows hypsarrhythmia. Which drug is preferred?
1. AVigabatrin
2. BCarbamazepine
3. CPhenytoin
4. DEthosuximide
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Answer: A · Vigabatrin
Infantile spasms with developmental regression and hypsarrhythmia are West syndrome, and ash-leaf macules suggest tuberous sclerosis as the cause. Vigabatrin, an irreversible inhibitor of GABA transaminase that raises brain GABA, is the drug of choice for spasms due to tuberous sclerosis. For most other causes, ACTH or oral prednisolone is used first. Vigabatrin can cause irreversible concentric visual field loss, so its duration is limited and vision is monitored.
- B: Carbamazepine is ineffective in infantile spasms and may worsen generalised seizures.
- C: Phenytoin does not control infantile spasms.
- D: Ethosuximide is used for absence seizures and does not control infantile spasms.
Question 6 · Medium
A 15-year-old girl from Jaipur has had low mood, withdrawal from friends, poor sleep and falling marks for 3 months, with no psychotic or manic features. Her depression is moderate to severe and has not improved after 6 weeks of psychotherapy. The child psychiatrist decides to add an antidepressant. Which drug is preferred?
1. AParoxetine
2. BVenlafaxine
3. CAmitriptyline
4. DFluoxetine
Answer and explanation in LearnFree account
Question 7 · Medium
A 27-year-old man with schizophrenia has made two serious suicide attempts in the past year in response to voices telling him to harm himself. He took risperidone and then olanzapine regularly, each at an adequate dose for 8 weeks, without benefit; his family supervises every dose. Which antipsychotic is most appropriate now?
1. AHaloperidol decanoate
2. BClozapine
3. CQuetiapine
4. DAripiprazole
Answer and explanation in LearnFree account
Question 8 · Medium
A 58-year-old woman has taken haloperidol for 9 years. Her daughter notices constant lip smacking, tongue rolling and writhing finger movements that worsen when she is anxious and disappear in sleep. Which class of drug can reduce these movements?
1. ABeta-blocker such as propranolol
2. BVMAT2 inhibitor such as tetrabenazine
3. CDopamine precursor such as levodopa
4. DAnticholinergic such as trihexyphenidyl
Answer and explanation in LearnFree account
Question 9 · Medium
A 30-year-old woman with bipolar I disorder is stable on lithium. The psychiatry resident writes her long-term monitoring plan: 1. Serum lithium 12 hours after a dose, every 3 months in the first year. 2. TSH every 6 months. 3. Serum creatinine and eGFR every 6 months. 4. Monthly liver function tests, because lithium is metabolised in the liver. Which parts of the plan are correct?
1. A1 and 2 only
2. B1, 2 and 4 only
3. C1, 2 and 3 only
4. D1, 3 and 4 only
Answer and explanation in LearnFree account
Question 10 · Medium
A 45-year-old woman on escitalopram for depression is given tramadol after a wrist fracture. Next day she is agitated and sweating, with temperature 38.6°C, pulse 118/min, dilated pupils, diarrhoea, brisk reflexes and inducible clonus in both ankles. Both drugs are stopped and supportive care begins. Which drug acts as a specific antidote?
1. ADantrolene
2. BFlumazenil
3. CCyproheptadine
4. DBromocriptine
Answer and explanation in LearnFree account
Question 11 · Medium
A 55-year-old woman with depression is about to start an SSRI. She also takes low-dose aspirin. Consider four statements about SSRIs: 1. Sexual dysfunction is a common adverse effect. 2. Paroxetine has the longest half-life, so withdrawal symptoms are least likely with it. 3. Hyponatraemia can occur, especially in older adults. 4. Taken with aspirin or NSAIDs, they raise the risk of gastrointestinal bleeding. Which statements are correct?
1. A1, 2 and 3 only
2. B1 and 4 only
3. C3 and 4 only
4. D1, 3 and 4 only
Answer and explanation in LearnFree account
Question 12 · Hard
A 34-year-old woman took paroxetine for 8 months for panic disorder. Feeling well, she stopped it abruptly 3 days ago. She now has dizziness, brief 'electric-shock' sensations in her head when she moves her eyes, irritability, nausea, vivid dreams and flu-like aches. She is afebrile with normal reflexes and no clonus, and she has had no panic attacks. What is the best management?
1. ARestart paroxetine and taper it slowly
2. BTreat as relapse of panic with clonazepam
3. CTreat as serotonin syndrome with cyproheptadine
4. DOrder an MRI brain to look for demyelination
Answer and explanation in LearnFree account
Question 13 · Hard
A 34-year-old man with schizophrenia had his haloperidol dose raised 5 days ago. He is now confused, with temperature 40.1°C, profuse sweating, BP swinging between 160/100 and 100/60 mmHg and generalised lead-pipe rigidity. Reflexes are normal and there is no clonus. CK is 18,000 U/L and TLC 15,000/µL. Haloperidol is stopped, and cooling and IV fluids are started. Which drug is appropriate next?
1. AChlorpromazine
2. BDantrolene
3. CTrihexyphenidyl
4. DCyproheptadine
Answer and explanation in LearnFree account
Question 14 · Medium
A 35-year-old woman with schizophrenia has been well on olanzapine for 2 years but has gained 14 kg. Her waist is 96 cm, fasting glucose 118 mg/dL, triglycerides 260 mg/dL and HDL 36 mg/dL. She wants to continue treatment. Which antipsychotic is best to switch to?
1. AClozapine
2. BAripiprazole
3. CQuetiapine
4. DChlorpromazine
Answer and explanation in LearnFree account
Question 15 · Medium
A 38-year-old man has been stable on lithium for 8 years with levels of 0.6-0.8 mEq/L. He now passes about 6 litres of urine a day and is always thirsty. Serum sodium is 145 mmol/L and urine osmolality 120 mOsm/kg, which barely rises after desmopressin. Other mood stabilisers have failed, so lithium must continue. Which drug is best to reduce his polyuria?
1. AHydrochlorothiazide
2. BDesmopressin
3. CFurosemide
4. DAmiloride
Answer and explanation in LearnFree account
Question 16 · Hard
A 24-year-old man was started on escitalopram by a general practitioner for depression 3 weeks ago. His family now says he sleeps 2 hours a night, talks fast, has spent his savings on mobile phones and claims he will soon lead the country. His sister recalls a 2-week spell last year of high energy and overspending that settled on its own. What is the best management?
1. AStop escitalopram and start a mood stabiliser
2. BContinue escitalopram and add clonazepam
3. CContinue escitalopram at a higher dose
4. DSwitch escitalopram to amitriptyline
Answer and explanation in LearnFree account
Question 17 · Easy
A 58-year-old schoolteacher with early Parkinson disease and mild tremor is started on selegiline alone by the neurology OPD, to delay the need for levodopa. Which enzyme does this drug inhibit at the usual dose?
1. AMonoamine oxidase A
2. BCatechol-O-methyltransferase
3. CDopa decarboxylase
4. DMonoamine oxidase B
Answer and explanation in LearnFree account
Question 18 · Easy
A 7-year-old girl is brought to the paediatric OPD because her teacher says she 'daydreams' many times a day. Each spell lasts about 10 seconds, with a blank stare and eyelid flicker, and one is provoked in the OPD by asking her to hyperventilate. EEG shows generalised 3 Hz spike-and-wave discharges. She has never had a convulsion or jerks. Which drug is preferred?
1. APhenobarbitone
2. BPhenytoin
3. CEthosuximide
4. DCarbamazepine
Answer and explanation in LearnFree account
Question 19 · Medium
A 64-year-old man has had Parkinson disease for 6 years and takes levodopa-carbidopa three times a day. His stiffness and slowness return 2-3 hours after each dose, before the next one is due. He has no troublesome dyskinesia. Which addition will best smooth his response?
1. ATrihexyphenidyl
2. BPyridoxine
3. CAmantadine
4. DEntacapone
Answer and explanation in LearnFree account
Question 20 · Easy
A 17-year-old boy from Kochi often drops his tea cup because of sudden jerks of the arms in the first hour after waking. After a night of studying for exams he had a generalised tonic-clonic seizure. EEG shows generalised polyspike-and-wave discharges. Which drug is most appropriate?
1. APhenytoin
2. BCarbamazepine
3. CSodium valproate
4. DEthosuximide
Answer and explanation in LearnFree account
Question 21 · Medium
A 26-year-old woman with generalised epilepsy on sodium valproate has lamotrigine added by a local practitioner, at the usual starting dose and with a quick increase. Three weeks later she has fever, target lesions, painful oral ulcers, conjunctival erosions and skin detachment over 8% of her body surface. Why was her risk of this reaction higher?
1. AValproate inhibits lamotrigine glucuronidation
2. BValproate shares an HLA-linked allergy
3. CValproate induces lamotrigine metabolism
4. DLamotrigine displaces valproate from albumin
Answer and explanation in LearnFree account
Question 22 · Easy
A 68-year-old man has had Parkinson disease for 7 years. A drug was added a year ago because of levodopa-induced dyskinesia. He now has a purplish, lace-like mottling of the skin of both legs and ankle swelling. Which drug is most likely responsible?
1. AEntacapone
2. BTrihexyphenidyl
3. CSelegiline
4. DAmantadine
Answer and explanation in LearnFree account
Question 23 · Easy
A 66-year-old retired bus conductor with Parkinson disease is started on a tablet combining levodopa with carbidopa. Why is carbidopa added?
1. AIt inhibits COMT in the periphery
2. BIt directly stimulates D2 receptors
3. CIt inhibits MAO-B in the brain
4. DIt blocks peripheral dopa decarboxylase
Answer and explanation in LearnFree account

Antiepileptics, antidepressants, antipsychotics and anti-Parkinson drugs

A 19-year-old college student has myoclonic jerks of the arms soon after waking, worse after late nights, and had one generalised tonic-clonic seizure last week. EEG shows generalised polyspike-and-wave discharges. She may want children in a few years. Which drug is the best first choice for her?

A 70-year-old woman with Parkinson disease is started on levodopa-carbidopa and develops nausea and vomiting after each dose. Which antiemetic is preferred?

A 7-month-old boy from Bihar has clusters of sudden flexion of the trunk and arms on waking, and he has lost the ability to sit. He has three hypopigmented ash-leaf macules on the trunk. EEG shows hypsarrhythmia. Which drug is preferred?

A 58-year-old woman has taken haloperidol for 9 years. Her daughter notices constant lip smacking, tongue rolling and writhing finger movements that worsen when she is anxious and disappear in sleep. Which class of drug can reduce these movements?

A 35-year-old woman with schizophrenia has been well on olanzapine for 2 years but has gained 14 kg. Her waist is 96 cm, fasting glucose 118 mg/dL, triglycerides 260 mg/dL and HDL 36 mg/dL. She wants to continue treatment. Which antipsychotic is best to switch to?

A 58-year-old schoolteacher with early Parkinson disease and mild tremor is started on selegiline alone by the neurology OPD, to delay the need for levodopa. Which enzyme does this drug inhibit at the usual dose?

A 64-year-old man has had Parkinson disease for 6 years and takes levodopa-carbidopa three times a day. His stiffness and slowness return 2-3 hours after each dose, before the next one is due. He has no troublesome dyskinesia. Which addition will best smooth his response?

A 17-year-old boy from Kochi often drops his tea cup because of sudden jerks of the arms in the first hour after waking. After a night of studying for exams he had a generalised tonic-clonic seizure. EEG shows generalised polyspike-and-wave discharges. Which drug is most appropriate?

A 68-year-old man has had Parkinson disease for 7 years. A drug was added a year ago because of levodopa-induced dyskinesia. He now has a purplish, lace-like mottling of the skin of both legs and ankle swelling. Which drug is most likely responsible?

A 66-year-old retired bus conductor with Parkinson disease is started on a tablet combining levodopa with carbidopa. Why is carbidopa added?