Side effects of tricyclic antidepressants

The side effects of tricyclic antidepressants are largely attributable to the ability of these compounds to bind to and block receptors for endogenous transmitter substances. These effects develop acutely. Antagonism at muscarinic cholinoceptors leads to atropine-like effects such as tachycardia, inhibition of exocrine glands, constipation, impaired micturition, and blurred vision. 

The efficacy of imipramine has been repeatedly demonstrated in controlled trials about 85% of children treated within a week of the start of medication, but tolerance frequently develops after a number of weeks and relapse is high after discontinuation of the treatment. Relatively low doses of imipramine only are needed, but the typical side effects of tricyclic antidepressants limit the prolonged use of the drug. The mechanism of action of imipramine in the treatment of nocturnal enuresis is unclear but one possible action is through a direct anticholinergic action on the bladder wall. 

Quader SE. Dysarthria an unusual side effect of tricyclic antidepressants. BMJ 1977 2(6079) 97. 

Slome BA. Rampant caries a side effect of tricyclic antidepressant therapy. Gen Dent 1984 32(6) 494-6. 

Leucht S, Hackl HJ, Steimer W, Angersbach D, Zimmer R. Effect of adjunctive paroxetine on serum levels and side-effects of tricyclic antidepressants in depressive inpatients. Psychopharmacology (Berl) 2000 147(4) 378-83. 

MEOTA also antagonized side effects of tricyclic antidepressants and protected AChE against inhibition by some organophosphate anticholinesterase compounds. 

In order for medications to be effective, they must be taken at an adequate dose (see figure 14-D). There seems to be a threshold effect, with subtherapeutic doses producing little or no benefit. However, achieving effective doses may be difficult due to the side effects of tricyclic antidepressants and MAOIs. Blood levels may be helpful to check the adequacy of tricylic dosage (see figure 14-E). 

Bupropion is a well-tolerated antidepressant. It is non-sedating and lacks the cardiovascular and anticholinergic side effects of tricyclic antidepressants. Bupropion s most commonly observed adverse effects are insomnia and dry mouth. The drug is also known to be associated with a low rate of seizures however, no seizure incidents were reported in the smoking cessation clinical trials. Other less frequently occurring side effects include nervous system disturbances (mainlytremor) and skin rashes (170,182). 

The main side effects of tricyclic antidepressants are sedation, anti-cholinergic effects (dry mouth, constipation and urinary retention) and postural hypotension. Some patients may experience mania, seizures or impotence. Tricyclic antidepressants should be used with caution in patients with liver disease. 

State the general side effects of tricyclic antidepressants. 

Drug Interactions Contraceptive effects are decreased when "the pill" is taken with ANTIDIOTICS (ampicillin, isoniazid, neomycin, pen V, rifampin, sulfonamides, tetracycline) or CNS AGENTS (barbiturates, benzodiazepines, phenytoin). Contraceptives increase the effects of corticosteroids and worsen side effects of tricyclic antidepressants. Oral contraceptives decrease the effectiveness of oral anticoagulants, anticonvulsants, and oral hypoglycemic agents. 

Atypicai Antipsychotics. In the 1980s and early 1990s, the SSRIs began a revolution in the treatment of depression. Tried-and-true but side effect laden tricyclic antidepressants fell into disfavor as newer and safer medications became available. A similar revolution is taking place in the treatment of psychosis. A new generation of antipsychotics that have fewer of the more disturbing side effects and may well be more effective are now available. 

Antidepressants. There are numerous reasons to expect that antidepressants may be helpful in the treatment of AN. First, depressed mood and other symptoms of depression such as anhedonia, decreased energy, poor concentration, and psychomotor retardation are common in cases of starvation from any cause. Second, AN patients and their family members have high rates of comorbid MDD and OCD, illnesses best treated with antidepressant medications. Finally, weight gain is a well-documented side effect of many antidepressants including the tricyclic antidepressants (TCAs) and mirtazapine. 

Nortriptyline. Nortriptyhne, a tricychc antidepressant, has been shown in double-blind, placebo-controlled randomized trials to be superior to placebo for smoking cessation (Prochazka et al. 1998). Nortriptyline appears to have efficacy comparable to that of bupropion for smoking cessation (Hall et al. 2002). The efficacy of this agent may be improved with more intensive behavioral therapies (Hall et al. 1998). Nortriptyline s mechanism of action is thought to relate to its noradrenergic and serotonergic reuptake blockade, because these two neurotransmitters have been implicated in the neurobiology of nicotine dependence. Side effects of nortiptyline are typical of tricyclic antidepressants and include dry mouth, blurred vision, constipation, and orthostatic hypotension. Nortriptyline appears to have some utility for smokers with a past history of major depression, and it can be recommended as a second-... 

Interaction with drug metabolism liquorices, which are the most commonly used herbs in TCM can increase metabolites (e.g., nortriptyline, desipramine, and norclomipramine) of tricyclic antidepressants (TCAs) and may produce more side effects (such as dry mouth, constipation, palpitation, etc.) (Xu, 2004 Zhu Huang, 2004). 

Although probably equally effective, the tricyclic antidepressants are usually avoided because of anticholinergic side effects. 

Common side effects of the SSRIs are somnolence, nausea, ejaculation disorders, decreased libido, dry mouth, insomnia, and fatigue. Tricyclic antidepressants (TCAs) commonly cause sedation, orthostatic hypotension, anticholinergic effects, and weight gain. TCAs are very toxic on overdose. 

Tricyclic drugs have, as the name implies, a three-ring structure, and interfere with reuptake of norepinephrine and/or serotonin into axon terminals. Tricyclic drugs include imipramine (Tofranil), amitriptyline (Elavil), clomipramine (Anafranil), and nortriptyline (Pamelor, Aventil). Tricyclics have the occasional but unfortunate cardiovascular side effects of arrhythmia and postural hypotension. Newer, nontricyclic antidepressants have been developed that are collectively referred to as SSRIs. These have a potent and selective action on serotonin, and lack the cardiovascular side effects of the tricyclics. These include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), and fluvoxamine (Luvox). A fifth SSRI, citalopram (Celexa) has been used in Europe and has recently been approved in the United States. Venlafaxine (Effexor) blocks reuptake of norepinephrine and serotonin, while bupropion (Wellbutrin) acts on both dopamine and norepinephrine. 

Tricyclic Antidepressants (TCAs). TCAs were introduced in the 1950s and over the years have become the mainstay of treatment for cataplexy and the other REM-related symptoms. The doses used are usually less than the doses required in the treatment of depression. Imipramine (Tofranil) is the most widely used TCA for narcolepsy and is usually effective at doses from 10 to 75 mg given once a day. Some doctors prefer the TCA protriptyline (Vivactil) because it has mild stimulant effects, but it has not been as widely used or as thoroughly studied in narcolepsy. The common side effects of TCAs are drowsiness, dry mouth, and constipation, but these are usually not a problem at the lower doses used for narcolepsy. Patients should receive a baseline electrocardiograph (EKG) before starting a TCA and should have blood levels of the medication checked periodically. 

One of the main side-effects of opioid analgesics, such as codeine and tramadol, is constipation. Amitriptyline (tricyclic antidepressant) and orphenadrine tend to have antimuscarinic properties, resulting in side-effects such as constipation. Senna is a stimulant laxative indicated in constipation. 

Thus, while there is suggestive, but conflicting, evidence that therapeutic response is related to plasma steady-state levels of tricyclic antidepressant drugs, the position as regards toxic side effects is uncertain. 

The efficacy of fluoxetine in treating patients with moderate depression is comparable to the efficacy of tricyclic antidepressants. It is capable of elevating mood and removing feelings of fear and stress. It does not have a sedative effect. Fluoxetine is used in depression as well as in bulemic neuroses. Use of fluoxetine is preferred in cases when sedative, hypotensive, and anticholinergic side effects caused by other antidepressants are con-traindicative to patients. Prozac is a synonym for fluoxetine. 

Although the efficacy of tricyclic antidepressants in the treatment of unipolar depression is beyond reproach, the side-effect profile of these agents makes them less desirable as first-line therapeutic agents. Introduction of selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, paroxetine, sertraline, citalopram and fluvoxamine in the past decade has revolutionized the treatment of depression universally. The side-effect profile of SSRIs, such as nausea, diarrhea and sexual dysfunction, is considerably more benign than that of tricyclic drugs. Multiple controlled trials have proven the efficacy of SSRIs vs. placebo (Nemeroff, 1994). Recently, a number of SNRIs (serotonin and noradrenaline reuptake inhibitors) and so-called atypical antidepressants have been marketed that may have additional advantages over SSRIs, such as more rapid onset of action (venlafaxine. mirtazapine) and low sexual side-effect potential ( bupropion, nefazodone). Additionally, it appears that venlafaxine may be more efficacious in cases of treatment-refractory depression (Clerc et al., 1994 Fatemi et al., 1999). Finally, in a recent report (Thase et al., 2001),... 

In terms of side effects of the tricyclic antidepressants (Table 6—5), blockade of alpha 1 adrenergic receptors causes orthostatic hypotension and dizziness (Fig. 6—30). Anticholinergic actions at muscarinic cholinergic receptors cause dry mouth, blurred vision, urinary retention, and constipation and memory disturbances (Fig. 

---