Coffee

Arabian coffee, cafe, caffea, Coffea arabica, espresso, java, mocha

The medicinal components of coffee are derived from the seeds, or beans. Coffee seeds contain 1% to 2% caffeine, 0.25% trigonelline, 3% to 5% tannins, 15% glucose and dextrin, 10% to 13% fatty oil (trioleoyl glycerol and tripalmitoyl glycerol), and 10% to 13% proteins.

Caffeine, the active component of coffee, acts as a central nervous system stimulant. It has positive chronotropic effects on the heart, may increase gastric secretions, and may relax smooth muscles of the blood vessels and the bronchioles of the respiratory tract. Caffeine may increase low density lipoproteins and total cholesterol levels in those consuming more than 5 cups of coffee per day. It also acts as a mild diuretic. Coffee is available as whole beans and as dried, freeze-dried, or ground beans. Spray-dried crystals are used for instant coffee.

Reported uses

Coffee is used most notably for its stimulant effects and for its ability to relieve malaise and weariness. It's also used for its diuretic and anti-inflammatory effects. In large doses, caffeine can be used to dilate the bronchioles during an asthma attack.

Administration

• Maximum dose of caffeine: 1.5 g per day; less than 250 mg per day for nonpregnant adults; usually, 100 to 150 mg (1 cup brewed coffee) per day for pregnant adults.

Hazards

Adverse effects associated with coffee include insomnia, irritability, nervousness, dizziness, headache, hypertension, tachycardia, palpitations, irregular heart rate, ulcers, heartburn, vomiting, diarrhea, loss of appetite, abdominal spasms, stiffness, muscle spasms, tachypnea, increased total cholesterol and low-density lipoprotein (LDL) levels, hyperglycemia, and increased excretion of calcium. Reduced sedative effects are seen when coffee is used in conjunction with benzodiazepines. Slight increase in blood pressure may occur when coffee is used with beta blockers (metoprolol, propranolol). Coffee charcoal may interfere with the absorption of other drugs. Significant elevation in blood pressure and mania may occur when coffee is used with phenylpropanolamine. Increased stimulant effects and side effects may occur when used with other caffeine or ephedrine-containing herbal or drug products. Coffee may potentiate the adverse effects of theophylline and increase jitteriness.

Caffeine is believed to increase the risk oflate first and second trimester miscarriages. Caffeine consumed by a breast-feeding mother can cause sleep disorders in her infant. Patients who are pregnant, breast-feeding, or planning pregnancy should avoid use. Patients with ulcers or chronic digestive disorders and those with hypertension should also avoid use.

Clinical considerations

Safety Risk Although lethal overdose is unlikely, the first signs and symptoms of poisoning are vomiting and abdominal spasms.

• Sustained intake of coffee can lead to physical dependence. Withdrawal symptoms include headache and sleep disorders.
• Advise patient with risk factors for heart disease, such as increased cholesterollevel or hypertension, to discuss caffeine consumption with his health care provider.
• Advise patient to inform his health care provider if he experiences difficulty sleeping or develops stomach upset or irritation. Discuss other potential adverse effects with patient and instruct him to promptly report signs and symptoms.
• Advise patient who's pregnant, breast-feeding, or planning pregnancy to Consider avoiding or limiting her caffeine intake.
• Tell patient to remind prescriber and pharmacist of any herbal or dietary supplement that he's taking when obtaining a new prescription.
• Advise patient to consult his health care provider before using an herbal preparation because a treatment with proven efficacy may be available.

Research summary

The concepts behind the use of coffee and the claims made regarding its effects have not yet been validated scientifically.