Plasma levels of nortriptyline and 10-hydroxynortriptyline and treatment-related electrocardiographic changes in the elderly depressed

Thirty-one elderly depressed patients were treated for seven weeks with nortriptyline with plasma levels kept between 50-180 ng/ml. Electrocardiograms were taken at the third and seventh weeks of treatment. There were significant increases in the PR interval, QTc interval, and heart rate from before and after treatment. However, there were no consistent correlations between electrocardiographic changes during treatment and plasma levels of nortriptyline, 10-hydroxynortriptyline and either of its two isomers (E-10-hydroxynortriptyline, Z-10-hydroxynortriptyline). Increased QRS duration after seven weeks of treatment was correlated with daily dose of nortriptyline.     

Dose and plasma levels of nortriptyline and chlorpromazine in delusionally depressed adolescents and of nortriptyline in nondelusionally depressed adolescents

Eight adolescents with major depressive disorder were treated with nortriptyline and six adolescents with delusional depression were treated with combined nortriptyline and chlorpromazine. Dose and plasma levels of nortriptyline for the two groups were compared. The delusional group receiving combined drug treatment needed significantly less nortriptyline than did the nondelusional group receiving only nortriptyline to obtain similar mean steady state plasma levels of the drug. The mean plasma chlorpromazine levels were quite low.     

Simultaneous measurement of various antidepressants in the plasma of depressed patients by high performance liquid chromatography

A simultaneous analytical method was reported for measuring the plasma levels of amitriptyline, imipramine, clomipramine, maprotiline, nortriptyline, desipramine, desmethylclomipramine, desmethylmaprotiline and amoxapine by high performance liquid chromatography (HPLC). The total plasma levels of each parent drug plus its desmethyl metabolite were monitored in 29 depressed patients administered with amitriptyline, maprotiline or amoxapine using the present analytical method. There were significant linear correlations between the dose per kg body weight and the total plasma levels with amitriptyline and maprotiline, but no such correlation was found with amoxapine. The ratios of total plasma levels to dose per kg body weight of these three drugs were lower in outpatients than in inpatients. These results indicate that the monitoring of plasma levels of antidepressants is useful in treating depression.     

Relationship of free nortriptyline levels to therapeutic response

The relationship between the free plasma concentration of nortriptyline and therapeutic response was examined. Eighteen depressed inpatients were treated for 21 days with steady state total nortriptyline plasma concentrations between 50-150 ng/ml. Steady state free nortriptyline concentrations were measured. The therapeutic nortriptyline response was measured by administering the Hamilton and the Carroll Rating scales at day zero and day 21. Statistical relationships between free levels of drug and clinical response were found to be insignificant. Qualitative assessment of the data suggest that free serum levels of nortriptyline in excess of 10 ng/ml may have an inhibitory effect on clinical response.     

Citalopram versus nortriptyline in late-life depression: a 12-week randomized single-blind study

OBJECTIVE: The aim of this single-blind study was to examine the efficacy and tolerability of citalopram compared to nortriptyline in moderate to severe major depressive patients aged 60 years or over. Method: In- and out-patients (N=58) with unipolar major depression were randomized to 12-week flexible dose treatment with nortriptyline or citalopram. RESULTS: No significant differences between the number of drop-outs in either group were observed, but the autonomic side-effects were significantly higher for nortriptyline than for citalopram. A significantly higher remission rate to nortriptyline than to citalopram was demonstrated, particularly if severe patients (endogenous or psychotic patients) were assessed. CONCLUSION: The remission rate to a therapeutic plasma level of nortriptyline appears to be higher than the remission rate to a standard dose of citalopram in a group of elderly major depressed patients, especially those with endogenous or psychotic features. On the other hand, citalopram appears to be better tolerated.     

Plasma levels and effects of nortriptyline in geriatric depressed patients

Pharmacokinetic, therapeutic effects, and side effects of nortriptyline were studied in geriatric depressed patients treated with a standard dose of 150 mg/day. Plasma levels and elimination half-life of nortriptyline were no different in geriatric patients than younger patients. The antidepressant therapeutic effects of nortriptyline appeared to be similar in geriatric patients as in younger depressed patients. Geriatric patients experienced few subjective side effects of nortriptyline. Overall, the drug produced no clinically significant changes in several parameters of the EKG, and no geriatric patient experienced tachycardia on nortriptyline. Nortriptyline did induce significant orthostatic hypotension in the systolic component, but not in the diastolic component. However, the orthostatic hypotension produced by nortriptyline was not greater in geriatric patients than in younger patients treated with the same dose.     

Plasma and erythrocyte levels of tricyclic antidepressants in depressed patients.

Plasma and red blood cells (RBCs), amitriptyline, nortriptyline, imipramine, desipramine, doxepin, and desmethyl doxepin levels were measured in depressed inpatients during steady-state kinetics. A strong positive correlation between the drug levels in plasma and RBCs was found for amitriptyline, nortriptyline, desipramine, and desmethyl doxepin. However, at a given plasma level, up to a 6-fold interindividual variation in the RBC drug levels was found. The correlations between plasma and RBC imipramine and doxepin levels were low. The interindividual variation in the RBC-plasma tricyclic level ratios was large enough to warrant further clinical studies on the relationship between efficacy and pharmacokinetics of tricyclic antidepressants.     

Drug treatment of depression in frail elderly nursing home residents.

The authors conducted a randomized, double-blind, 10-week clinical trial of two doses of nortriptyline in eight nursing homes. Sixty-nine patients, average age 79.5 years, were randomized to receive regular doses (60 mg-80 mg/day) vs. low doses (10 mg-13 mg/day) of nortriptyline. Among the more cognitively intact patients, there was a significant quadratic relationship defining a "therapeutic window" for nortriptyline plasma levels and clinical improvement. There were also significant differences in plasma level-response relationships between depressed patients who were cognitively impaired and those who were more cognitively intact. Depression remains a syndrome that responds to specific treatment, even in frail nursing home patients, and those depressions that occur in patients with significant dementia may represent a treatment-relevant condition with a different plasma level-response relationship than in depression alone.     

Plasma 10-hydroxynortriptyline and ECG changes in elderly depressed patients

Among 18 elderly depressed patients given ECGs before and during nortriptyline treatment, plasma E-10-hydroxynortriptyline and the sum of E-10-hydroxynortriptyline and nortriptyline distinguished the group with conduction/repolarization effects. Plasma nortriptyline, age, drug dose, and baseline cardiovascular status did not.     

Treatment of major depression with nortriptyline and paroxetine in patients with ischemic heart disease.

OBJECTIVE: This study compared the efficacy, tolerability, and safety of paroxetine and nortriptyline in depressed patients with ischemic heart disease. METHOD: After a 2-week, single-blind placebo lead-in phase, 81 outpatients with DSM-III-R-defined nonpsychotic unipolar major depression and ischemic heart disease were randomly assigned to double-blind treatment with paroxetine or nortriptyline for 6 weeks. Paroxetine was administered at a fixed-flexible dose of 20-30 mg/day. Nortriptyline dose was adjusted with the use of blood-level monitoring to reach a plasma concentration of 50-150 ng/ml. RESULTS: Twenty-seven of the 41 patients who started treatment with paroxetine and 29 of the 40 patients who started treatment with nortriptyline had an improvement of at least 50% in their Hamilton Depression Rating Scale scores. Significantly more patients taking nortriptyline discontinued treatment prematurely (35% versus 10%), and more patients taking nortriptyline had adverse events resulting in termination (25% versus 5%). CONCLUSIONS: Both treatments were efficacious. Sixty-three percent of all patients improved at least 50%, and of these, 90% met the criteria for remission. Paroxetine was better tolerated than nortriptyline and less likely to produce cardiovascular side effects.     

MAO inhibition and control of anxiety following amitriptyline therapy

In a pilot study, 32 patients with mixed states of anxiety, depression, somatization and panic received amitriptyline for 4 weeks, the dose ranging from 50 to 300 mg/day. Steady-state plasma levels of the drug and activity of platelet monoamine oxidase were measured after 4 weeks. Clinical change was rated, using the SCL-90. Amitriptyline produced a small but significant inhibition of platelet monoamine oxidase activity (range 1.4–82%). A significant positive correlation was noted between MAO inhibition and improvement on somatization, and psychological and panic-phobic components of anxiety, but not for depression. No significant correlations were observed between improvement and combined or separate ami- + nortriptyline plasma levels.     

Nortriptyline in geriatric depression resistant to serotonin reuptake inhibitors: case series

Research on treatment-resistant depression in the elderly has been limited, and recommendations for clinical management have often been extrapolated from studies using nongeriatric patients. This report describes a series of 10 elderly patients with refractory depression who were treated with nortriptyline after failing to respond to an adequate trial of a serotonin reuptake inhibitor. Seven (70%) of the patients responded to the addition or substitution of nortriptyline. All seven of the responders have remained on nortriptyline for maintenance therapy, none of whom have experienced recurrence of their depression after an average treatment duration of 1 year. Response to nortriptyline occurred in about 4 weeks in most patients. The mean daily dose of nortriptyline was 54 mg, and the mean plasma level was 97 ng/mL. Minor side effects occurred in three patients. No patients developed significant electrocardiogram changes. Nortriptyline, possibly due to its different mechanism of action, may be effective as either an adjunctive or replacement antidepressant in some cases of geriatric depression that are resistant to serotonin reuptake inhibitors.     

Salivation after single-doses of the new antidepressants femoxetine, mianserin and citalopram. A cross-over study

Twelve healthy volunteers were given oral single doses of a reference drug (nortriptyline), test drugs, and placebo on a randomised single-blind basis at weekly intervals. The doses corresponded to average daily patient medication. Spontaneous whole mouth salivation was measured before (at 10 p.m.) and 10 hours after drug administration (at 8 a.m.). Drug plasma levels were determined after 4 and 10 hours. When analysing the salivations 10 hours after drug administration adjusted for the effects of the pre-treatment salivations, statistically significant inhibition of salivation was found after nortriptyline (56%), femoxetine (34%), and mianserin (29%) when compared with placebo, while for citalopram and cis- and trans-flupenthixol no significant inhibition of salivation was demonstrated (Fig. 1, Table 5). From the estimated log linear regression coefficients, relating adjusted salivation rates and drug plasma levels 10 hours after drug administration (Table 6), and reported average steady-state plasma drug levels (Table 7), semiquantitative predictions of the average level of anticholinergic activity during long-term treatment may be made: For femoxetine and mianserin, moderate anticholinergic activity, less pronounced than with nortriptyline, are predicted, while for citalopram no such activity can be predicted (Table 7).     

Valpromide-amitriptyline interaction. Increase in the bioavailability of amitriptyline and nortriptyline caused by valpromide

Valpromide is largely used in the therapy of affective disorders for its presumed thymoregulating activity. So, it is often associated with tricyclic antidepressant treatment. Previous clinical studies lead us to consider the possibility of an interaction between valpromide and tricyclic antidepressants, interaction which could result in an increase of antidepressant plasma concentrations. But no pharmacokinetic study has been realized up to now in order to clearly demonstrate such a phenomenon. The authors studied amitriptyline and nortriptyline plasma levels in two groups of ten patients receiving 125 mg amitriptyline, once a day, during 20 days. In the second group, patients also received 600 mg valpromide daily after ten days on amitriptyline. In the first group amitriptyline and nortriptyline plasma concentrations remained stable between the tenth and the twentieth day. In the second group, addition of valpromide resulted in a significant increase of antidepressant plasma levels: from 70.5 +/- 35 to 105.5 +/- 49 ng/ml (p less than 0.0003) for amitriptyline, and from 61.0 +/- 34 to 100.5 +/- 65 ng/ml (p less than 0.01) for nortriptyline.     

Pharmacokinetics of psychotropic drugs: What can it tell us?

1. Knowledge of basic pharmacokinetic parameters may help the clinician to optimize drug treatment regimen. 2. For some psychotropic drugs (e.g. lithium and some antidepressants) a good correlation exists between plasma levels and therapeutic or toxic effects. 3. "Optimum" steady state levels can now be predicted from single dose blood level data of some drugs (lithium, nortriptyline, desipramine). 4. Altered pharmacokinetics in elderly and children have to be taken into consideration in treatment with psychotropic drugs. 5. With development of suitable drug assays, plasma level control of therapy is becoming a part of a good clinical practice.     

Open-trial maintenance pharmacotherapy in late-life depression: survival analysis

We report preliminary findings from an ongoing, open trial of maintenance nortriptyline pharmacotherapy in 27 elderly depressed patients (median trial length: 18 months). While patients were on maintenance nortriptyline (mean dose: 50 mg/day) with steady-state plasma levels in the range of 50-150 ng/ml, 58% of Q-6 monthly ratings on the Hamilton Rating Scale for Depression have been 10 or lower, Folstein Mini-Mental State ratings have remained above 27, and a minimal level of side effects with no increase over time has been observed. Four of 27 patients (14.8%) have suffered recurrences and have required rehospitalization at 6, 9, 10, and 13 months. Survival analysis showed an 85% survival rate (without recurrence) at 12 months and 81.5% at 18 months. Mean survival time without recurrence is 21.3 months to date. Although our pilot experience with maintenance nortriptyline in late-life depression appears more favorable than outcomes reported in earlier naturalistic studies (where no attempt was made to keep patients in systematic maintenance therapy), the need for controlled studies of maintenance therapies in late-life depression is nonetheless underscored by the current data and other naturalistic data from the United Kingdom.     

Treating delusional depressives with amitriptyline

Thirty-five delusional depressed patients were treated for either 28 or 35 days with amitriptyline. The 12 responders could not be differentiated from the nonresponders on a variety of demographic and clinical characteristics. Patients with amitriptyline+nortriptyline plasma levels above 250 ng/ml were significantly more likely to be responders than were patients with levels below that value (p less than .05). A review of the relevant literature revealed that, although some delusional depressives do respond to treatment with tricyclic antidepressants, the presence of delusions is a predictor of poor response to tricyclic antidepressants.     

Single oral dose pharmacokinetics of amitriptylinoxide and amitriptyline in humans

Eleven healthy volunteers were examined in a pharmacokinetic study. After oral administration of 50 mg amitriptylinoxide or 50 mg amitriptyline the plasma levels of amitriptylinoxide and its main metabolites amitriptyline and nortriptyline were investigated over 24 hours. The results indicate that amitriptylinoxide is more rapidly absorbed than amitriptyline and eliminated with a mean half-life of 1.5 hours. The change with time in the levels of amitriptyline formed from the oxide is similar to that of amitriptyline after ingestion of amitriptyline. However, the plasma concentration of amitriptylinoxide, reflected by the area under the time curve (AUC), exceeds that of its metabolite amitriptyline twelvefold.     

Significance of monitoring plasma levels of amitriptyline, and its hydroxylated and desmethylated metabolites in prediction of the clinical outcome of depressive state

Abstract The clinical significance of monitoring the plasma levels of amitriptyline and its metabolites in prediction of the clinical outcome of depressive episode was investigated in 49 inpatients. Discriminant analysis of drug concentrations (at two weeks after initiation of drug treatment) and clinical outcome revealed that increasing the plasma levels of amitriptyline, cis-isomers of hydroxylated metabolites (Z-10-hydroxyamitriptyline and Z-10-hydroxynortriptyline) predicted a better clinical outcome, while increasing of plasma levels of nortriptyline and trans-isomers of hydroxylated metabolites (E-10-hydroxyamitriptyline and E-10-hydroxynortriptyline) were shown to predict a poor clinical outcome in the depressive episode of the subjects, and that clinical outcome of approximately 73% of the subjects could be correctly predicted.     

Drug interaction between rifampin and nortriptyline: a case report

This case illustrates a pharmacokinetic interaction between the tricyclic antidepressant, nortriptyline, and the antituberculosis drug, rifampin. Higher than expected doses of nortriptyline were required to obtain a therapeutic drug level while the patient was receiving rifampin. Following the discontinuation of rifampin, the patient became drowsy and the serum nortriptyline levels rose precipitously into the toxic range. The authors suggest that patients receiving rifampin and nortriptyline, (or other psychotropic drugs) be monitored closely and that similar drug interactions be anticipated.