The New Complete Book of Food
Increased risk of heartburn/acid reflux. The natural oils in both regular and decaffeinated
coffees loosen the lower esophageal sphincter (LES), a muscular valve between the esopha-
gus and the stomach. When food is swallowed, the valve opens to let food into the stomach,
then closes tightly to keep acidic stomach contents from refluxing (flowing backwards) into
the esophagus. If the LES does not close efficiently, the stomach contents reflux and cause
heartburn, a burning sensation. Repeated reflux is a risk factor for esophageal cancer.
Masking of sleep disorders. Sleep deprivation is a serious problem associated not only with
automobile accidents but also with health conditions such as depression and high blood pres-
sure. People who rely on the caffeine in a morning cup of coffee to compensate for lack of
sleep may put themselves at risk for these disorders.
Withdrawal symptoms. Caffeine is a drug for which you develop a tolerance; the more often
you use it, the more likely you are to require a larger dose to produce the same effects and
the more likely you are to experience withdrawal symptoms (headache, irritation) if you
stop using it. The symptoms of coffee-withdrawal can be relieved immediately by drinking
a cup of coffee.Food/Drug Interactions
Drugs that make it harder to metabolize caffeine. Some medical drugs slow the body’s
metabolism of caffeine, thus increasing its stimulating effect. The list of such drugs includes
cimetidine (Tagamet), disulfiram (Antabuse), estrogens, fluoroquinolone antibiotics (e.g.,
ciprofloxacin, enoxacin, norfloxacin), fluconazole (Diflucan), fluvoxamine (Luvox), mexi-
letine (Mexitil), riluzole (Rilutek), terbinafine (Lamisil), and verapamil (Calan). If you are
taking one of these medicines, check with your doctor regarding your consumption of caf-
feinated beverages.
Drugs whose adverse effects increase due to consumption of large amounts of caffeine.
This list includes such drugs as metaproterenol (Alupent), clozapine (Clozaril), ephedrine,
epinephrine, monoamine oxidase inhibitors, phenylpropanolamine, and theophylline. In
addition, suddenly decreasing your caffeine intake may increase blood levels of lithium, a
drug used to control mood swings. If you are taking one of these medicines, check with your
doctor regarding your consumption of caffeinated beverages.
Allopurinol. Coffee and other beverages containing methylxanthine stimulants (caffeine,
theophylline, and theobromine) reduce the effectiveness of the antigout drug allopurinol,
which is designed to inhibit xanthines.
Analgesics. Caffeine strengthens over-the-counter painkillers (acetaminophen, aspirin, and
other nonsteroidal anti-inflammatories [NSAIDS] such as ibuprofen and naproxen). But it
also makes it more likely that NSAIDS will irritate your stomach lining.
Antibiotics. Coffee increases stomach acidity, which reduces the rate at which ampicillin,
erythromycin, griseofulvin, penicillin, and tetracyclines are absorbed when they are taken
by mouth. (There is no effect when the drugs are administered by injection.)