Gastrointestinal system adverse drug effects

Adverse Effects. Quinine is associated with many adverse effects involving several primary organ systems. This drug may produce disturbances in the CNS (headache, visual disturbances, ringing in the ears), gastrointestinal system (nausea, vomiting, abdominal pain), and cardiovascular system (cardiac arrhythmias). Problems with hypersensitivity, blood disorders, liver dysfunction, and hypoglycemia may also occur in some individuals. 

Adverse effects With chronic use, procainamide causes a high incidence of side effects, including a reversible lupus erythe-matosus-like syndrome that develops in 25 to 30% of patients. Toxic concentrations of procainamide may cause asystole or induction of ventricular arrhythmias. Central nervious system (CNS) side effects include depression, hallucination and psychosis. With this drug, gastrointestinal intolerance is less frequent than with quinidine. 

EossUen, E. Adverse effects of nonsteroidal antiinflammatory drugs on the gastrointestinal system. Ann. Clin. Lab. Sci. 1998,28, 67—81. 

Adverse effects of tetracyclines include resistant bacteria, folliculitis, candidiasis, gastrointestinal upset, and phototoxic effects. Tetracyclines must not be combined with systemic retinoids because of the increased probability for development of intracranial hypertension. Tetracycline is used in the treatment of moderate to severe acne vulgaris. It is the least expensive of the tetracyclines and therefore often prescribed for initial therapy. A common initial approach includes tetracycline 1 g daily (500 mg twice daily), 1 hour before meals after 1 or 2 months, when marked improvement of inflammatory lesions is observed, the dose may be decreased to 500 mg every day, for another 1 or 2 months. Drawbacks to the use of tetracycline include also a drug-food interaction with dairy prodncts. 

The adverse side effects of bisphosphonates are renal toxicity, acute-phase reactions, gastrointestinal toxicity, hypocalcemia, ocular complications, asthma erythema, phlebitis, altered taste, and central nervous system side effects. The osteonecrosis of the jaw is the emerging one (Diel et ah, 2007 Tanvetyanon and Stiff, 2006). To overcome this kind of problem, researchers are now turning toward nature-based drugs. 

As with all drugs, the specific side effects of the quinolones must be considered when they are chosen for treatment of bacterial infections [5]. Reactions of the gastrointestinal tract and the central neivous system are the most often observed adverse effects during therapy with quinolones. It should be underlined, however, that compared with many other antimicrobials, diarrhea is less frequently observed during quinolone treatment. Antibiotic-associated colitis has been observed rarely during quinolone therapy. Similarly, hypersensitivity reactions, as observed during therapy with penicillins and other (3-lactams, is less frequently caused by quinolones. Some other risks of quinolone therapy have been defined and must be considered if a drug from this class is chosen for treatment of bacterial infections. 

Sulfasalazine has a high incidence of adverse effects, most of which are attributable to systemic effects of the sulfapyridine molecule. Slow acetylators of sulfapyridine have more frequent and more severe adverse effects than fast acetylators. Up to 40% of patients cannot tolerate therapeutic doses of sulfasalazine. The most common problems are dose-related and include nausea, gastrointestinal upset, headaches, arthralgias, myalgias, bone marrow suppression, and malaise. Hypersensitivity to sulfapyridine (or, rarely, 5-ASA) can result in fever, exfoliative dermatitis, pancreatitis, pneumonitis, hemolytic anemia, pericarditis, or hepatitis. Sulfasalazine has also been associated with oligospermia, which reverses upon discontinuation of the drug. Sulfasalazine impairs folate absorption and processing hence, dietary supplementation with 1 mg/d folic acid is recommended. 

Adverse Effects. The primary adverse effect of systemic pentamidine administration is renal toxicity. Renal function may be markedly impaired in some patients, but kidney function usually returns to normal when the drug is withdrawn. Other adverse effects include hypotension, hypoglycemia, gastrointestinal distress, blood dyscrasias (leukopenia, thrombocytopenia), and local pain and tenderness at the site of injection. Adverse effects are reduced substantially when the drug is given by inhalation, and this method of administration is desirable when pentamidine is used to prevent pneumocystis pneumonia in patients with human immunodeficiency virus (HIV) disease. 

One tablet given daily for 12 weeks achieves a cure rate of up to 90% for onychomycosis and is more effective than griseofulvin or itraconazole. Adverse effects are rare, consisting primarily of gastrointestinal upset and headache. Terbinafine does not seem to affect the P450 system and has demonstrated no significant drug interactions to date. 

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