Doxycyclineinteractions

Patients on anticoagulant therapy may require downward adjustment of their anticoagulant dosage. Some bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline-class drugs in conjunction with penicillin. The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity.

7.1 Anticoagulants

Because tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage.

7.2 Penicillin

Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline-class drugs in conjunction with penicillin.

7.3 Methoxyflurane

The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity.

7.4 Antacids and

Iron Preparations Absorption of tetracyclines is impaired by bismuth subsalicylate, proton pump inhibitors, antacids containing aluminum, calcium or magnesium and iron-containing preparations.

7.5 Oral Retinoids

There have been reports of pseudotumor cerebri (benign intracranial hypertension) associated with the concomitant use of isotretinoin and tetracyclines. Since both oral retinoids, including isotretinoin and acitretin, and the tetracyclines, primarily minocycline, can cause increased intracranial pressure, the concurrent use of an oral retinoid and a tetracycline should be avoided.

7.6 Barbiturates and

Anti-epileptics Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline.

7.7 Drug/Laboratory

Test Interactions False elevations of urinary catecholamine levels may occur due to interference with the fluorescence test.