Diclofenamide

Pregnancy Category C.

There are no adequate and well-controlled studies in pregnant women. Teratogenic effects (fetal limb reduction defects) were reported following oral administration of dichlorphenamide to pregnant rats during organogenesis at 350 mg/kg, or 17 times the maximum recommended human dose (200 mg/day) on a body surface area (mg/m²) basis. A no-effect dose has not been established. Diclofenamide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

It is not known whether dichlorphenamide is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when dichlorphenamide is administered to a nursing woman.

Carcinogenesis

Studies to assess the carcinogenic potential of dichlorphenamide have not been conducted.

Mutagenesis

Studies to assess the genotoxicity of dichlorphenamide have not been conducted.

Impairment of Fertility

Studies to assess the effects of dichlorphenamide on fertility have not been conducted.

• Hypersensitivity / Anaphylaxis / Idiosyncratic reactions
• Hypokalemia
• Metabolic Acidosis
• Falls

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In a 9-week randomized controlled trial in adults with hyperkalemic or hypokalemic periodic paralysis (Study 1), the most common adverse reactions in patients treated with diclofenamide, with rates greater than placebo, were paresthesia, cognitive disorder, dysgeusia, and confusional state. The mean dose of diclofenamide was 94 mg/day in patients with hypokalemic periodic paralysis and 82 mg/day in patients with hyperkalemic periodic paralysis.

The table below lists the incidence of adverse reactions that occurred in ≥5% of patients treated with diclofenamide and more commonly than in patients treated with placebo in Study 1.

Adverse Reactions in Patients Treated with Diclofenamide with Incidence ≥5% and more common than in Patients Treated with Placebo in Study 1:

* Cognitive disorder combined cases with the preferred terms of cognitive disorder, disturbance in attention, and mental impairment.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of dichlorphenamide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The following are adverse reactions which have been reported for dichlorphenamide that were serious adverse events or are not reported in the previous section of labeling: amnesia, cardiac failure, condition aggravated, convulsion, fetal death, hallucination, nephrolithiasis, pancytopenia, psychotic disorder, renal tubular necrosis, stupor, syncope, tremor.