Medical Today

Pharmacology.

Leflunomide’s active metabolite (M1) inhibits dihydro-oratate dehydrogenase, thereby inhibiting pyrimidine biosynthesis. M1 exhibits immunomodulating and anti-inflammatory effects.

Administration and Adult Dosage.

PO for rheumatoid arthritis 100 mg/day for 3 days, then 20 mg/day. Reduce dose to 10 mg if 20 mg is not tolerated.

Pediatric Dosage.

Safety and efficacy not established.

Geriatric Dosage.

Same as adult dosage.

Dosage Forms.

Pharmacology.
Ifosfamide is a structural analogue of the alkylating agent cyclophosphamide (CTX). The rate of hepatic conversion of ifosfamide to the active metabolite 4-hydroxyifosfamide is slightly slower than with CTX, although formation of the bladder toxin acrolein is not reduced. The ultimate metabolite ifosforamide mustard cross-links DNA to impair cell division. The drug is always given with mesna to prevent urotoxicity. Although labeled for use in refractory testicular cancer, ifosfamide also has useful activity against soft tissue sarcoma, malignant lymphoma, and small cell lung cancer. Ifosfamide is cell-cycle phase nonspecific.

Pharmacology.
Venlafaxine is a potent reuptake inhibitor of serotonin and norepinephrine, like many TCAs, but lacks effects on muscarinic,

Administration and Adult Dosage.
PO for depression (immediate-release) 75mg bid or tid initially, increasing q 4-7 days to an effective antidepressant dosage of 225-375 mg/day in 2 or 3 divided doses; (sustained-release) 75 mg once daily initially, increasing in increments of up to 75 mg/day at intervals of 4 or more days to a maximum of 225 mg/day. The sustained-release preparation does not reduce side effects but allows once-daily administration.
PO for generalized anxiety disorder 75-225 mg/day in 2-3 divided doses. Patients with renal impairment or on hemodialysis require a 25-50% dosage reduction.