Susceptible groups of patients, such as children and the elderly, are at greater risk of adverse reactions during therapeutic use.Ofloxacin, like some other fluoroquinolones, may inhibit drug-metabolizing enzymes, and thereby increase blood levels of other drugs such as cyclosporine, theophylline, and warfarin, among others. These increased blood levels may result in a greater risk of side effects. Careful monitoring of serum glucose is advised when ofloxacin or other fluorquinolones are used by people who are taking sulfonylurea antidiabetes drugs. The concomitant administration of a nonsteroidal anti-inflammatory drug with a quinolone, including ofloxacin, may increase the risk of central nervous system stimulation and convulsive seizures. The fluoroquinolones have been shown to increase the anticoagulant effect of acenocoumarol, anisindione, and dicumarol. Additionally, the risk of cardiotoxicity and arrhythmias is increased when co-administered with drugs such as dihydroquinidine barbiturate, quinidine, and quinidine barbiturate.Current or past treatment with oral corticosteroids is associated with an increased risk of Achilles tendon rupture, especially in elderly patients who are also taking the fluoroquinolones. Contraindications
As noted above, under licensed use, ofloxacin is now considered to be contraindicated for the treatment of certain sexually transmitted diseases by some experts due to bacterial resistance. Caution should be used in people with liver disease. The excretion of ofloxacin may be reduced in patients with severe liver function disorders (e.g., cirrhosis with or without ascites). Ofloxacin is also considered to be contraindicated within the pediatric population, pregnancy, nursing mothers, patients with psychiatric illnesses and in patients with epilepsy or other seizure disorders.
Risk is substantially elevated in the elderly and in those with recent exposure to topical or systemic corticosteroid therapy. Simultaneous use of corticosteroids is present in almost one-third of quinolone-associated tendon rupture. Tendon damage may manifest during and up to a year after fluoroquinolone therapy has been completed.Fluoroquinolones prolong the QT interval by blocking voltage-gated potassium channels. Prolongation of the QT interval can lead to torsades de pointes, a life-threatening arrhythmia, but in practice, this appears relatively uncommon in part because the most widely prescribed fluoroquinolones (ciprofloxacin and levofloxacin) only minimally prolong the QT interval.Clostridium difficile-associated diarrhea may occur in connection with the use of any antibacterial drug, especially those with a broad spectrum of activity such as clindamycin, cephalosporins, and fluoroquinolones. Fluoroquinoline treatment is associated with risk similar to or less than that associated with broad spectrum cephalosporins. Fluoroquinoline administration may be associated with the acquisition and outgrowth of a particularly virulent Clostridium strain.The U.S. prescribing information contains a warning regarding uncommon cases of peripheral neuropathy, which can be permanent. Other nervous system effects include insomnia, restlessness, and rarely, seizure, convulsions, and psychosis Other rare and serious adverse events have been observed with varying degrees of evidence for causation.Events that may occur in acute overdose are rare, and include kidney failure and seizure.