Drug Interactions

Question 1

What drug needs to be stopped 3 days before I 131 treatment and started 3 days after I 131 treatment

Answer 1

Methimazole

Question 2

What develops when given with insulin or its analogues?

How to treat?*

Answer 2

Hypoglycemia

By glucose and not sucrose as sucrase is inhibited by this drug

Question 3

Alpha glucosidase are C/I in which other conditions and why?

Answer 3

IBD, colonic ulceration or intestinal obstruction
(As it worsen by excessive gas formation)

Question 4

Gliptins

Answer 4

GLP 1 analogues
(As overlapping mechanisms and toxocity)

Question 5

Insulin
(10)

Answer 5

ẞ adrenergic blockers
prolong hypoglycaemia by inhibiting compensatory mechanisms operating through ẞ, receptors (B, selective blockers are less liable). Warning signs of hypoglycaemia like palpitation, tremor and anxiety are masked.

Thiazides
Furosemide
Corticosteroids
Oral contraceptives
Salbutamol
Nifedipine tend to raise blood sugar and reduce effectiveness of insulin.

Acute ingestion of
Alcohol can precipitate hypoglycaemia by depleting hepatic glycogen

Lithium
high dose aspirin
Theophylline may also accentuate hypoglycaemia by enhancing insulin secretion, as well as peripheral glucose utilization

Question 6

Sulfonylureas
Reduce its effect (6)
Increase its effect (8)

Answer 6

Drugs that may reduce the effects of

sulfonylureas, leading to loss of glucose control:

Atypical antipsychotics

Corticosteroids

Diuretics

Niacin

Phenothiazines

Sympathomimetics

Drugs that may potentiate the effects of sulfonylureas, leading to hypoglycemia:

• Azole antifungals

• B-Blockers

• Chloramphenicol

• Clarithromycin

• Monoamine oxidase inhibitors

• Probenecid

• Salicylates

• Sulfonamides

Question 7

Sulfonylureas

Answer 7

Glinides

should not be used in combination with sulfonylureas due to overlapping mechanisms of action and increased risk of serious hypoglycemia

Alcohol

Question 8

Glinides (2)

Answer 8

Gemfibrozil

By inhibiting hepatic metabolism, the lipid-lowering drug gemfibrozil may significantly increase the effects of repaglinide, and concurrent use is contraindicated.

Sulfonylureas

Question 9

Docusates

Answer 9

By a detergent action, it can disrupt the mucosal barrier and enhance absorption of many nonabsorbable drugs, e.g. liquid paraffin-should not be combined with it.

Question 10

Laxatives in general

Answer 10

certain drugs, e.g.-opiates, sedatives, anticholinergics including antiparkinsonian, antidepressants and antihistaminics, oral iron, clonidine, verapamil

Question 11

Metoclorpramide blocking DA receptors in basal ganglia,
it abolishes the therapeutic effect of

Answer 11

Levodopa

Question 12

The rate of absorption of some
drugs, e.g. aspirin, diazepam, digoxin may
be altered by the gastric hurrying action of

Answer 12

Metoclorpramide

Question 13

Promethazine, diphen-
hydramine, diazepam or lorazepam injected
i.v. along with metoclopramide supplement for

Answer 13

its antiemetic action and reduce the attending
dystonic reactions.