Foods: Milk Doxycycline

Tetracyclines. It is important to give the tetracyclines on an empty stomach tetracyclines are not to be taken with dairy products (milk or cheese). The exceptions are doxycycline (Vibramycin) and minocycline (Minocin), which may be taken with dairy products or food. The nurse should give clindamycin with food or a full glass of water. The nurse can give troleandomycin and clarithromycin without regard to meals. All tetracyclines should be given with a full glass of water (240 mL). 

These antibiotics are partially absorbed from the stomach and upper gastrointestinal tract. Food impairs absorption of all tetracyclines except doxycycline and minocycline. Absorption of doxycycline and minocy-cbne is improved with food. Since the tetracyclines form insoluble chelates with calcium (such as are found in many antacids), magnesium, and other metal ions, their simultaneous administration with milk (calcium), magnesium hydroxide, aluminum hydroxide, or iron will interfere with absorption. Because some of the tetracyclines are not completely absorbed, any drug remaining in the intestine may inhibit sensitive intestinal microorganisms and alter the normal intestinal flora. 

The absorption of tetracycline administered orally is variable and depend upon the type of tetracycline used. The tetracycline form insoluble complexes i.e. chelation with calcium, magnesium, milk and antacids reduce their absorption. Administration of iron also interferes with the absorption of tetracycline. Doxycycline is rapidly and virtually completely absorbed after oral administration and its absorption is not affected by presence of food or milk. 

The oral dosage for rapidly excreted tetracyclines, equivalent to tetracycline hydrochloride, is 0.25-0.5 g four times daily for adults and 20-40 mg/kg/d for children (8 years of age and older). For severe systemic infections, the higher dosage is indicated, at least for the first few days. The daily dose is 600 mg for demeclocycline or methacycline, 100 mg once or twice daily for doxycycline, and 100 mg twice daily for minocycline. Doxycycline is the oral tetracycline of choice because it can be given as a once-daily dose and its absorption is not significantly affected by food. All tetracyclines chelate with metals, and none should be orally administered with milk, antacids, or ferrous sulfate. To avoid deposition in growing bones or teeth, tetracyclines should be avoided in pregnant women and children less than 8 years of age. 

Milk and dairy foods decrease the absorption of some tetracyclines (doxycycline and minocycline are not affected), some quinolone antibiotics (absorption of ciprofloxacin and norfloxacin is decreased but ofloxacin is not affected), penicillamine and alendronate. Large volumes of milk can reduce the ulcer-healing properties of bismuth tripotassium dicitratobismuthate (bismuth chelate),... 

In a contained casualty setting, children with inhalation anthrax can receive intravenous antibiotics in a mass casualty setting and as postexposure prophylaxis, children can receive oral antibiotics (Inglesby et al., 2002). Doxycycline is dispensed in a tablet that children may not be able to swallow however, it can be ground and mixed with food or drink to make it palatable. Palatable foods and drinks for mixing doxycycline include chocolate pudding, chocolate milk, low-fat chocolate milk, simple syrup with sour apple flavor. 

It is produced by semisynthesis from other tetracycline molecules and is the most widely used of the tetracycline family. Doxycycline is well absorbed on oral administration (90-100% when fasting reduced by 20% by co-consumption with food or milk), has a half-life permitting once-a-day dosing for mild infections, and is excreted partly in the feces and partly in the urine. 

An active substance, although initially released from its dosage form (and dissolved), may become unavailable for absorption due to reactimis with other medicines or food components [4]. An example is the formation of insoluble complexes of tetracycline with calcium or aluminium ions from antacids or milk products. Interaction (chelation or binding) with iron ions leads to a reduced absorption for a variety of active substances such as doxycycline, penicillamine, methyldopa and ciprofloxacin. The absorption of active substances showing pH-dependent dissolution behaviour may be influenced by medicines that influence the gastric pH, such as H2-antagonists, proton pump inhibitors and antacids. Antimycotic active substances such as ketoconazole or itraconazole dissolve better in acidic fluids. Therefore their bioavailability may be increased by the concomitant use of an acidic drink like cola, whereas the concomitant use of antacids or proton pump inhibitors is likely to reduce the bioavailability. Concomitant use of milk may increase the dissolution of acidic active substances, whereas fats from food may increase the bioavailability of lipophilic active substances like albendazole and griseofulvin. 

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