be about half of that given to younger adults and are to be administered for no longer than two weeks. Long-acting benzodiazepines such as clonazepam are not generally recommended for the elderly due to the risk of drug accumulation. The elderly are especially susceptible to increased risk of harm from motor impairments and drug accumulation side effects. Benzodiazepines also require special precaution if used by individuals that may be pregnant, alcohol- or drug-dependent, or may have comorbid psychiatric disorders. Clonazepam is generally not recommended for use in elderly people for insomnia due to its high potency relative to other benzodiazepines. Clonazepam is not recommended for use in those under 18. Use in very young children may be especially hazardous. Of anticonvulsant drugs, behavioural disturbances occur most frequently with clonazepam and phenobarbital. Doses higher than 0.5–1 mg per day are associated with significant sedation. Clonazepam may aggravate hepatic porphyria. Clonazepam is not recommended for patients with chronic schizophrenia. A 1982 double-blinded, placebo-controlled study found clonazepam increases violent behavior in individuals with chronic schizophrenia. Clonazepam has similar effectiveness to other benzodiazepines at often a lower dose. Interactions Clonazepam decreases the levels of carbamazepine, and, likewise, clonazepam's level is reduced by carbamazepine. Azole antifungals, such as ketoconazole, may inhibit the metabolism of clonazepam. Clonazepam may affect levels of phenytoin (diphenylhydantoin). In turn, Phenytoin may lower clonazepam plasma levels by increasing the speed of clonazepam clearance by approximately 50% and decreasing its half-life by 31%. Clonazepam increases the levels of primidone and phenobarbital. Combined use of clonazepam with certain antidepressants, anticonvulsants (such as phenobarbital, phenytoin, and carbamazepine), sedative antihistamines, opiates, and antipsychotics, nonbenzodiazepines (such as zolpidem), and alcohol may result in enhanced sedative effects. Pregnancy There is some medical evidence of various malformations (for example, cardiac or facial deformations when used in early pregnancy); however, the data is not conclusive. The data are also inconclusive on whether benzodiazepines such as clonazepam cause developmental deficits or decreases in IQ in the developing fetus when taken by the mother during pregnancy. Clonazepam, when used late in pregnancy, may result in the development of a severe benzodiazepine withdrawal syndrome in the neonate. Withdrawal symptoms from benzodiazepines in the neonate may include hypotonia, apnoeic spells, cyanosis, and impaired metabolic responses to cold stress. The safety profile of clonazepam during pregnancy is less clear than that of other benzodiazepines, and if benzodiazepines are indicated during pregnancy, chlordiazepoxide and diazepam