Clinical response,plasma levels and pharmacokinetics of desiramine in depressed in-patients

• 1.1. Correlation between clinical response and plasma levels was investigated in seven patients with endogenous depression treated with 2×1 mg/kg/day of desipramine (DMI) for 21 days. Clinical response was measured by reduction in Hamilton Depression Rating Scale (HDRS) scores.
• 2.2. A beneficial effect of DMI was seen in five out of seven patients studied and was fully evident already one week after the beginning of treatment.
• 3.3. Great inter-individual differences were observed in DMI plasma levels both after a single dose and at ‘steady state’. The maximum plasma concentration after a single dose (C_max) ranged between 19 and 179 ng/ml and the mean ‘steady state’ concentration between 65 and 240 ng/ml.
• 4.4. No significant correlation was found between HDRS scores and plasma levels of DMI; however, a plot of plasma levels and amelioration scores at the end (22nd day) of treatment was suggestive of a curvilinear relationship.
• 5.5. Post ‘steady state’ plasma disappearance half-lives of DMI calculation in four patients ranged from 11.5 to 34.3 hr (mean ± S.E.M. = 26.2 ± 5.0).