Pharmacology: Drugs Effects and Precautions

Study Notes

Antibiotics

Cephalosporins should be taken on an empty stomach to speed up absorption.
Erythromycin should not be taken with fruit juice or wine, as they decrease the drug's effectiveness.
Sulfa drugs increase the risk of vitamin B12 deficiency.
Tetracycline's effectiveness is reduced by dairy products, and it also lowers vitamin C absorption.

Anticonvulsants

Dilantin and phenobarbital increase the risk of anemia and nerve problems due to a deficiency in folate and other B vitamins.

Antidepressants

Fluoxetine reduces appetite and can lead to excessive weight loss.
Lithium's effectiveness is affected by salt intake: a low-salt diet increases the risk of lithium toxicity, while excessive salt reduces the drug's efficacy.
Monoamine oxidase (MAO) inhibitors interact with foods high in tyramine (e.g., aged cheeses, processed meats, legumes, wine, and beer), which can bring on a hypertensive crisis.
Tricyclics have reduced absorption when taken with certain foods, such as legumes, meat, fish, and foods high in vitamin C.

Antihypertensives and Heart Medications

Angiotensin-converting enzyme (ACE) inhibitors should be taken on an empty stomach to improve absorption.
Alpha-blockers should be taken with liquid or food to avoid an excessive drop in blood pressure.
Antiarrhythmic drugs interact with caffeine, which increases the risk of an irregular heartbeat.
Beta-blockers should be taken on an empty stomach, as food (especially meat) increases the drug's effects and can cause dizziness and low blood pressure.
Digitalis should be taken with caution, as milk and high-fiber foods reduce absorption, and it increases potassium loss.
Diuretics increase the risk of potassium deficiency.
Potassium-sparing diuretics should not be taken with potassium supplements or salt substitutes, unless advised by a doctor, to avoid potassium overload.
Thiazide diuretics increase the reaction to MSG.

Asthma Drugs

Pseudoephedrine interacts with caffeine, which increases feelings of anxiety and nervousness.
Theophylline's absorption is reduced by charbroiled foods and a high-protein diet, and caffeine increases the risk of drug toxicity.

Cholesterol-Lowering Drugs

Cholestyramine increases the excretion of folate and vitamins A, D, E, and K.
Gemfibrozil's efficacy is decreased by fatty foods.

Heartburn and Ulcer Medications

Antacids interfere with the absorption of many minerals and should be taken 1 hour after eating for maximum benefit.
Cimetidine, famotidine, and sucralfate interact with high-protein foods, caffeine, and other items that increase stomach acidity.

Hormone Preparations

Oral contraceptives reduce the absorption of folate, vitamin B6, and other nutrients, and increase the intake of foods high in these nutrients to avoid deficiencies.
Salty foods increase fluid retention when taking oral contraceptives.
Steroids also increase fluid retention with salty foods, and require increased intake of foods high in calcium, vitamin K, potassium, and protein to avoid deficiencies.

Thyroid Drugs

Iodine-rich foods may lower the drug's efficacy.

Laxatives

Mineral oils can cause a deficiency of vitamins A, D, E, and K if overused.

Painkillers

Aspirin and stronger nonsteroidal anti-inflammatory drugs (NSAIDs) should be taken with food to lower the risk of gastrointestinal irritation, and should not be taken with alcohol, which increases the risk of bleeding.

Description

Learn about the effects and precautions of different types of drugs, including antibiotics, anticonvulsants, and their interactions with food and nutrients. Understand how to take these medications effectively and avoid potential side effects.