Tricyclic antidepressants morphine

The major receptor-mediated adverse effect is water intoxication, which can occur with desmopressin or vasopressin. Many drugs, including carbamazepine, chlorpropamide, morphine, tricyclic antidepressants and NSAIDs, can potentiate the antidiuretic effects of these peptides, while lithium, demeclocycline and ethanol can attenuate the antidiuretic response to desmopressin. Desmopressin and vasopressin should be used cautiously when a rapid increase in extracellular water may impose risks (e.g., in angina, hypertension, and heart failure) and should not be used in patients with acute renal failure. Patients receiving desmopressin to maintain hemostasis should be... 

Drugs that may interact with rifabutin include the following Anticoagulants, azole antifungal agents, benzodiazepines, beta blockers, buspirone, corticosteroids, cyclosporine, delavirdine, doxycycline, hydantoins, indinavir, rifamycins, losartan, macrolide antibiotics, methadone, morphine, nelfinavir, quinine, quinidine, theophylline, aminophylline, tricyclic antidepressants, and zolpidem. 

Wahlstrom, A., Lenhammar, L., Ask, B., Rane, A. Tricyclic antidepressants inhibit opioid receptor binding in human brain and hepatic morphine glucuronidation. Pharmacol. Toxicol. 75(1), 23-27, 1994. 

The respiratory depression induced by morphine can add to that of alcohol, barbiturates, benzodiazepines (such as Valium), and even with antihistamines taken for allergies. Combined effects of these drugs with morphine can dangerously compromise breathing. Tricyclic antidepressants can hamper the metabolism of morphine. 

Drug interactions The depressant actions of morphine are enhanced by phenothiazines (see p. 127), monoamine oxidase inhibitors (see p.123), and tricyclic antidepressants (see p. 119 and Figure 14.5). Low doses of amphetamine (see p. 103) strangely enhance analgesia. Hydroxyzine (see p. 422) also enhances analgesia. 

Electrochemical detectors can be used in the oxidative mode for a wide range of drugs, including cannabinoids, haloperidol, morphine, paracetamol, phenothiazines, salicylic acid, and tricyclic antidepressants. Operation in the reductive mode is more difficult as dissolved oxygen must be removed from the eluent (K. Bratin et al, J. liq. Chromat., 1981,, 1777-1795). Reductive applications include chloramphenicol and benzodiazepines. 

Tricyclic antidepressants may reduce morphine requirement in palliative care without noticeably altering mood. 

Tricyclic antidepressants (and perhaps others) have a morphine-sparing effect even in the absence of an effect or mood. 

Interactions. Morphine (also pethidine and possibly other opioids) is potentiated by monoamine oxidase inhibitors. Any central nervous system depressant (including alcohol) will have additive effects. Patients recently exposed to neuromuscular blocking agents (unless this is adequately reversed, e.g. by neostigmine) are particularly at risk from the respiratory depressant effects of morphine. The effect of diuretic drugs may be reduced by release of antidiuretic hormone by morphine. Useful interactions include the potientating effect on pain relief of tricyclic antidepressants and of dexamfetamine. 

Conversely, the elimination of basic drugs such as amfetamine, antihistamines, morphine and tricyclic antidepressants can be increased by making tubular filtrate more acidic by administration of ammonium chloride. 

Chlorpromazine increases the respiratory-depressant effects of meperidine, as do tricyclic antidepressants this is not true of diazepam. Concurrent administration of drugs such as promethazine or chlorpromazine also may greatly enhance meperidine-induced sedation without slowing clearance of the drug. Treatment with phenobar-bital or phenytoin increases systemic clearance and decreases oral bioavailability of meperidine this is associated with an elevation of the concentration of normeperidine in plasma. As with morphine, concomitant administration of an amphetamine has been reported to enhance the analgesic effects of meperidine and its congeners while counteracting sedation. 

In most cases the mechanism is not known. Stimulators of vasopressin secretion include vincristine, cyclophosphamide, tricyclic antidepressants, nicotine, epinephrine, and high doses of morphine. Lithium, which inhibits the renal effects of vasopressin, also enhances vasopressin secretion. Inhibitors of vasopressin secretion include ethanol, phenytoin, low doses of morphine, glucocorticoids, fluphenazine, haloperidol, promethazine, oxilorphan, and butorphanol. Carba-mazepine has a renal action to produce antidiuresis in patients with central diabetes insipidus but actually inhibits vasopressin secretion via a central action. 

Amphetamine and related substances (G) Amphetamine (I) Methamphetamine (I) Barbiturates (G, I) Benzodiazepines (G, I) Cannabinoids (G, I) Methadone/metabolites (G, I) Cocaine/metabolites (G, I) Methaqualone/metabolites (G, I) Opiates (G) Codeine (I) Dihydrocodeine (I) Morphine (I) Phencyclidine/metabolites (G, I) Propoxyphene/metabolites (G, I) Tricyclic antidepressants (G, I)... 

A. Cimetidine, and to a lesser extent ranitidine, reduces hepatic clearance and prolongs the elimination half-life of several dmgs as a result of inhibition of cytochrome P-450 activity and reduction of hepatic blood flow. Examples of drugs affected include phenytoin, theophylline, phenobatbital, cyclosporine, morphine, lidocaine, calcium channel blockers, tricyclic antidepressants, and warfarin. 

The manufacturer states that nefopam should not be given to patients taking non-selective MAOIs and caution should be used in those taking tricyclic antidepressants, antimuscarinics and sym-pathomimetics. The intensity and incidence of adverse effects are somewhat increased when nefopam is given with codeine, pentazocine or dextropropoxyphene (propoxyphene), and the CNS depressant effect of dihydrocodeine may have contributed to a fatal overdose with nefopam. However, a morphine-sparing effect has been reported. Nefopam may also have a synergistic analgesic effect with ketoprofen. 

In general, the concurrent use of most opioids and tricyclics is uneventful, although lethargy, sedation, and respiratory depression have been reported. Tramadol should be used with caution with tricyclic antidepressants because of the possible risk of seizures and the serotonin syndrome. Dextroproposyphene may cause moderate rises in the serum levels of amitriptyline and nortriptyUne, and methadone may moderately raise desipramine levels. The bioavailability and the degree of analgesia of oral morphine is increased by clomipramine, desipramine and possibly amitriptyline. 

The CNS depressant effects of opioids and the tricyclic antidepressants are expected to be additive. The reasons for the increased morphine levels and analgesic effects that occur with some tricyclics are not understood. The increased analgesia may be due not only to the increased serum levels of morphine, but possibly also to some alteration in the way the morphine affects its receptors. Dextropropoxyphene probably inhibits liver metabolism of some tricyclic antidepressants by inhibiting the activity of the cytochrome P450 isoenzyme CYP2D6, and as a result the serum levels of the tricyclic antidepressants rise. It is suggested that the methadone may possibly inhibit the hydroxylation of the desipramine, thereby raising its levels. ... 

Abusive drugs + 700-1200 morphine and derivatives, benzodiazepines, cocaine, hallucinogens, tetrahydro-cannabinols, tricyclic antidepressants, neuroleptics... 

Morphine decreases the metabolism of tricyclic antidepressants, leading to toxicity. 

---