MDS PREP
Dry mouth during antidepressant therapy is caused by blockade of:
1) Muscarinic acetylcholine receptors.
2) Serotonergic receptors.
3) Dopaminergic receptors.
4) GABA receptors.
Pharmacology Answer: 1
Anticholinergic side effect of antidepressant leads to dry mouth in the patients on these drugs.
Dry mouth is due to the Muscarinic acetylcholine receptor antagonism of these drugs.
Drug implicated for prolonging QT interval in a premature baby is :
1) Domperidone
2) Metoclopramide
3) Cisapride
4) Omeprazole
Pharmacology Answer: 3
Cisapride can cause QT prolongation when administered along with drugs like ketoconazole which inhibit hepatic cytochrome p-450 CYP 3A4 enzyme.
One of the side-effects of prilocaine is
1) Gastric bleeding
2) Porphyria
3) Photophobia
4) Methemoglobinemia
Pharmacology Answer: 4
Methemoglobinemia is a condition in which the iron within hemoglobin is oxidized from the ferrous (Fe2+) state to the ferric (Fe3+) state, resulting in the inability to transport oxygen and carbon dioxide. Clinically, this condition causes cyanosis, often posing a diagnostic dilemma
usually results from exposure to oxidizing substances (such as nitrates or nitrites, aniline dyes, or medications, including lidocaine, prilocaine, phenazopyridine hydrochloride (Pyridium], and others)
The administration of barbiturates is contraindicated in :
1) Anxiety disorders
2) Acute intermittent prophyria
3) Kernicterus
4) Refractive status epilepticus
Pharmacology Answer: 2
Acute intermittent prophyria (AIP) : Barbiturates exacerbate it by inducing microsomal enzymes and d amino levulinic acid synthetase and increasing prophyrin synthesis.
Note: Contraindications of barbiturates : · Liver and kidney disease · Severe pulmonary insufficiency eg. Emphysema · Obstructive sleep apnoea
False statement regarding phenytoin is?
1) It is a teratogenic drug
2) Highly protein bound
3) Induces insulin secretion
4) Follows saturation kinetics
Pharmacology Answer: 3
Phenytoin inhibits insulin secretion and causes hyperglycemia.
The effects of hypoglycemia is marked by
1) Warfarin
2) Beta blockers
3) Calcium channel blockers
4) Amino glycosides
Pharmacology Answer: 2
Beta blockers
Hypoglycemia can occur with beta-blockade because b2- adrenoceptors normally stimulate hepatic glycogen breakdown (glycogenolysis) and pancreatic release of glucagon, which work together to increase plasma glucose.
Which drug is most effective in reducing mortality in patients with left ventricular systolic dysfunction ?
1) Enalapril
2) Aspirin
3) Digoxin
4) Frusemide
Pharmacology Answer: 1
ACE inhibition has a beneficial impact on survival rates, functional status, and hemodynamics in patients with left ventricular systolic dysfunction.
In the renin-angiotensin system, a fall in perfusion pressure stimulates the juxtaglomerular cells in the kidney to release the enzyme renin.
Renin cleaves the decapeptide angiotensin I from angiotensinogen, a glycoprotein synthesized in the liver.
The octapeptide angiotensin II is formed by the action of ACE on angiotensin I.
Angiotensin II is a potent vasoconstrictor and stimulates the release of aldosterone and norepinephrine.
Which of the following is the first drug to be prescribed in status asthmaticus?
1) Salbutamol
2) Humidified oxygen inhalation
3) Hydrocortisone hemisuccinate
4) Sodium bicarbonate infusion
Pharmacology Answer: 3
Status asthmaticus/Refractory asthma
Any patient of asthma is susceptible to develop acute severe asthma which may be life-threatening. Upper respiratory tract infection is the most common precipitant.
(i) Hydrocortisone hemisuccinate 100 mg (or equivalent dose of another glucocorticoid) i.v. stat, followed by 100-200 mg 4-8 hourly infusion; may take upto 6 hours to act.
(ii) Nebulized salbutamol (2.5-5 mg) + ipratropium bromide (0.5 mg) intermittent inhalations driven by O2 .
(iii) High flow humidified oxygen inhalation
(iv) Salbutamol/terbutaline 0.4 mg i.m./s.c. may be added since inhaled drug might not get to smaller bronchi owing to severe narrowing/plugging with secretions
(v) Intubation and mechanical ventilation if needed
(vi) intensive antibiotic therapy to be used for treating chest infection
(vii) Treat dehydration and acidosis with saline + sod. Bicarbonate/lactate infusion.