Tetracyclines Foods

Rx of pneumonia, skin, soft tissue Infxns, osteomyelitis caused by penicillinase-producing staphylococci Action Bactericidal X cell wall synth Dose Adults. 250-500 mg qid Feds <40 kg, 12.5-100 mg/kg/d - qid take on empty stomach Caution [B, ] Contra Component orPCN sensitivity Disp Caps 125, 250, 500 mg soln 62.5 mg/5 mL SE N/D, abd pain Interactions T Effects W/ disulfiram, probenecid T effects OF MRX, X effects W/ macrolides, tetracyclines, food X effects OF OCPs, warfarin EMS Monitor for signs of electrolyte disturbances and hypovolemia d/t D OD May cause N/V/D, behavior changes, urinary retention, skin rash and Szs symptomatic and supportive... 

There seem to be no direct clinical studies with calcium-containing antacids, but a clinically important interaction seems almost a certainty, based on in vitro studies with calcium carbonate, calcium in milk, (see Tetracyclines + Food or Drinks , p.347), dicalcium phosphate, and calcium as an excipient in tetracycline capsules. 

Patients should be warned about taking any antacids and indigestion preparations. Instead of using antacids to minimise the gastric irritant effects of the tetracyclines it is usually recommended that tetracyclines are taken after food, however it is not entirely clear how much this affects their absorption (see Tetracyclines + Food or Drinks , p.347). Hj-recep-tor antagonists may be suitable non-interacting alternatives to antacids in some situations, see Tetracyclines + Hj-receptor antagonists , p.348. 

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). 

There is an increased risk of toxicity of MTX when administered with the NSAIDs, salicylates, oral antidiabetic drugs, phenytoin, tetracycline, and probenecid. There is an additive bone marrow depressant effect when administered with other drug known to depress the bone marrow or with radiation therapy. There is an increased risk for nephrotoxicity when MTX is administered with other drug that cause nephrotoxicity. When penicillamine is administered with digoxin, decreased blood levels of digoxin may occur. There is a decreased absorption of penicillamine when the dmg is administered with food, iron preparations, and antacids. 

Tetracycline Tablets, capsules 250, 500 mg 500 mg twice daily before meals Maintenance dose 500 mg daily Gl upset, phototoxicity, tooth discoloration, drug and food interactions... 

There are problems as well in the absorption of certain drugs in the presence of specific food components. L-Dopa absorption may be inhibited in the presence of certain amino acids formed from the digestion of proteins [43], The absorption of tetracycline is reduced by calcium salts present in dairy foods and by several other cations, including magnesium and aluminum [115-117], which are often present in antacid preparations. In addition, iron and zinc have been shown to reduce tetracycline absorption [118], Figure 17 illustrates several of these interactions. These cations react with tetracycline to form a water-in-soluble and nonabsorbable complex. Obviously, these offending materials should not be co-administered with tetracycline antibiotics. 

OTC can be well separated from TC, DC, and its impurities by means of capillary electrophoresis [25]. However, the use of CE in the analysis of OTC residues is restricted because of the low concentration sensitivity of this technique [28]. HPLC is by far the most widely used method for the analysis of OTC residues in food and fisheries products. Chromatographic analysis of tetracycline including OTC analysis in foods was reviewed by Oka et al. [65] and MacNeil [72]. HPLC methods for the analysis of OTC are summarized in Table 2. 

Doxycycline is commonly used for moderate to severe acne vulgaris. It is more effective and produces less resistance than tetracycline. The initial dose is 100 or 200 mg daily, followed by 50 mg daily as a maintenance dose after improvement is seen. Doxycycline maybe given with food, but it is more effective when taken 30 minutes before meals. / Minocycline is also commonly used for moderate to severe acne vulgaris. It is more effective than tetracycline. It is dosed similar to doxycycline (100 mg/day or 50 mg twice daily) and on an indefinite basis in selected patients. Minocycline has the most reported adverse effects of the tetracyclines, some of which may be serious. 

Biosensors based on microbial immobilization have also been used for food applications, e.g., the inexpensive and rapid high-throughput bacterial biosensor developed by Virolainen et al. for rapid detection of tetracyclines and their 4-epimer derivatives in poultry meat [188, 189]. 

Administration of 100 mg doxycycline, in the absence of foods, led to almost complete absorption from the gut and a peak blood level of 1-8 Mg/ml two hours after ingestion. Three times this dose was required.to produce a similar blood level in four hours in the case of 300 mg demethylchlortetracycline. The plasma half-life (after single dose) was 15 hours in the case of doxycycline and 12 hours for demethylchlortetracycline. This means that the half-life of doxycycline is seven hours longer than that of tetracycline. 

The advisability of using certain antibiotics, particularly penicillin and tetracycline, in animal feeds has been questioned because of their use in human medicine. Any use of an antibiotic that is prescribed for humans presents some risks to human health, whether the use is for humans, animals or for other purposes but. the uses also have benefits. Otherwise, they would not persist. Antibiotics are used in animal feeds to increase animal weight, increase efficiency of feed utilization, increase reproductive efficiency and decrease morbidity and mortality. These benefits to animals and animal producers are reflected in decreases in food costs to humans. There are also benefits to human health from use of antibiotics in food animals. By reducing the incidence of animal health problems, use of antibiotics in food animals reduce the transference of animal infections to humans. The contention that the effectiveness of penicillin and tetracycline for use in human medicine is rapidly diminishing as a result of the proliferation of resistant bacteria caused by subtherapeutic use of antibiotics in animal production is not supported by experimental data. Rather, the evidence suggests that a fairly stable level of resistance of the intestinal bacteria in humans has long since been established to penicillin and tetracycline as it has been in animals. 

Since 1977, the Food and Drug Adminstration (FDA) has been considering a ban on the subtherapeutic use of procaine penicillin and tetracyclines in animal feeds. These antibiotics are used in both humans and animals, and any use of an antibiotic that is prescribed for humans presents some risk to human health, whether the use is for humans, animals, or other purposes. The risk is that pathogenic or disease-causing bacteria may develop a strain that resists that antibiotic. The resistant strain of the pathogen then may cause human disease that cannot be treated by this antibiotic. 

Some supporters of the proposed FDA ban on the use of subtherapeutic levels of penicillin and tetracyclines in animal feeds hailed the results of the CDC study as a clear link between subtherapeutic antibiotic use in food animal production and antibiotic-resistant diseases in humans. Some opponents, on the... 

Report on the Status of the Food and Drug Administration s Proposed Withdrawal of Approvals for Low Level uses of Penicillin and Tetracyclines in Animal Feeds," Subcommittee on Agriculture, Rural Development and Related Agencies, 1985. 

Since 1969, the Food and Drug Administration s Center for Veterinary Medicine (formerly the Bureau of Veterinary Medicine) has had cause for concern that the subtherapeutic use of antibiotics in animal feeds may cause bacteria in animals to become resistant to antibiotics. This resistance to antibiotics is said by many knowledgeable scientists to be transferred to bacteria in humans, thus making these antibiotics ineffective in treating human bacterial infections due to compromise of therapy. For this reason, FDA proposed in 1977 to withdraw the use of penicillin in animal feed and restrict the use of the tetracyclines (chlortetracycline and oxytetracycline) to certain uses in animal feed. This talk will focus on FDA s efforts to finalize its review of the issue and present an update on the current status of the 1977 proposals. 

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