Dichlorphenamide

5 WARNINGS AND PRECAUTIONS Hypersensitivity and Other Life-Threatening Reactions: discontinue dichlorphenamide at the first appearance of skin rash or any sign of immune-mediated or idiosyncratic adverse reaction ( 5.1 ) Hypokalemia: baseline and periodic measurements of serum potassium are recommended; if hypokalemia develops or persists, consider reducing the dose or discontinuing dichlorphenamide and correcting potassium levels ( 5.3 ) Metabolic acidosis: baseline and periodic measurements of serum bicarbonate are recommended; if metabolic acidosis develops or persists, consider reducing the dose or discontinuing dichlorphenamide ( 5.4 ) Falls: consider reducing the dose or discontinuing dichlorphenamide in patients who experience falls ( 5.5 ) 5.1 Hypersensitivity and Other Life-Threatening Reactions Fatalities associated with the administration of sulfonamides have occurred because of adverse reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia and other blood dyscrasias. Pulmonary involvement can occur in isolation or as part of a systemic reaction. Dichlorphenamide should be discontinued at the first appearance of skin rash or any sign of immune-mediated or other life-threatening adverse reaction. 5.2 Concomitant Use of Aspirin or Other Salicylates Carbonic anhydrase inhibitors, including dichlorphenamide, can cause metabolic acidosis [see Warnings and Precautions ( 5.4 )] , which can increase the risk of salicylate toxicity. Anorexia, tachypnea, lethargy, and coma have been reported with concomitant use of dichlorphenamide and high-dose aspirin. Therefore, the concomitant use of dichlorphenamide and high-dose aspirin is contraindicated. Patients with concomitant use of dichlorphenamide and low-dose aspirin should be carefully monitored. 5.3 Hypokalemia Dichlorphenamide increases potassium excretion and can cause hypokalemia. The risk of hypokalemia is greater when dichlorphenamide is used in patients with conditions associated with hypokalemia (e.g., adrenocortical excess, renal tubular acidosis type 1 and 2), and in patients receiving other drugs that may cause hypokalemia [see Drug Interactions ( 7.3 )] . Baseline and periodic measurements of serum potassium during dichlorphenamide treatment is recommended. If hypokalemia develops or persists, consideration should be given to reducing the dose or discontinuing dichlorphenamide and correction of potassium levels. 5.4 Metabolic Acidosis Dichlorphenamide can cause hyperchloremic non-anion gap metabolic acidosis. Concomitant use of dichlorphenamide with other drugs that cause metabolic acidosis may increase the severity of acidosis. Concomitant use of dichlorphenamide in compensated patients with respiratory acidosis, such as in advanced lung diseases, may lead to respiratory decompensation. Baseline and periodic measurements of serum bicarbonate during dichlorphenamide treatment are recommended. If metabolic acidosis develops or persists, consideration should be given to reducing the dose or discontinuing dichlorphenamide [see Drug Interactions ( 7.4) ]. 5.5 Falls Dichlorphenamide increases the risk of falls. The risk of falls is greater in the elderly and with higher doses of dichlorphenamide. Consider dose reduction or discontinuation of dichlorphenamide in patients who experience falls while treated with dichlorphenamide.

6 ADVERSE REACTIONS The following serious adverse reactions are described elsewhere in labeling: Hypersensitivity and Other Life-Threatening Reactions [see Warnings and Precautions ( 5.1 )] Hypokalemia [see Warnings and Precautions ( 5.3 )] Metabolic Acidosis [see Warnings and Precautions ( 5.4 )] Falls [ see Warnings and Precautions ( 5.5 )] Most common adverse reactions (incidence at least 10% and greater than placebo) include paresthesias, cognitive disorder, dysgeusia, and confusional state ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Rising Pharma Holdings, Inc. at 1-844-874-7464, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 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 dichlorphenamide, with rates greater than placebo, were paresthesia, cognitive disorder, dysgeusia, and confusional state. The mean dose of dichlorphenamide was 94 mg/day in patients with hypokalemic periodic paralysis and 82 mg/day in patients with hyperkalemic periodic paralysis. Table 1 lists the incidence of adverse reactions that occurred in ≥ 5% of patients treated with dichlorphenamide and more commonly than in patients treated with placebo in Study 1. Table 1: Adverse Reactions in Patients Treated with dichlorphenamide 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. diclorophenamide-Table 1.jpg 6.2 Postmarketing Experience 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 during postapproval use of dichlorphenamide and were serious or are not reported in the previous section of labeling [see Clinical Trials Experience ( 6.1 ) ]: amnesia, cardiac failure, condition aggravated, convulsion, hallucination, nephrolithiasis, pancytopenia, psychotic disorder, renal tubular necrosis, stupor, syncope, tremor.