Chemistry and Pharmacokinetics

Three xanthines are pharmacologically important: caffeine, theophylline, and theobromine. All three alkaloids, which occur naturally in certain plants, are widely consumed in the form of beverages (infusions or decoctions) derived from these plants. Coffee primarily contains caffeine (about 100-150 mg per average cup); tea contains caffeine (30-40 mg per cup) and theophylline; and cocoa contains caffeine (15-18 mg per cup) and theobromine. Cola drinks also contain significant amounts of caffeine (about 40 mg/12 oz). The CNS stimulation associated with these beverages is predominantly due to the caffeine.

The xanthines are readily absorbed by the oral and rectal routes. Although these agents can be administered by injection (aminophylline is a soluble salt of theophylline), intravascular administration is indicated only in status asthmaticus and apnea in premature infants. Intramuscular injection generally produces considerable pain at the injection site.

The compounds are extensively metabolized, primarily to uric acid derivatives. There is, however, no indication that methylxanthines aggravate gout.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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