Antidepressant and Antianxiety Drugs MCQs

Ans. A. Serotonine The three main neurotransmitters involved in depression are dopamine, norepinephrine and serotonin (s-HT). When brain Ievels of one or more neurotransmitter are low or unbalanced, depression can result. Generally, antidepressant drugs work by increasing production or decreasing the breakdown of one or more of these neurotransmitters.

Bronchospasm increases the resistance to airflow, which makes it more difficult to expel gas rapidly from the lung during expiration, so although both FEV1 and vital capacity decrease, the percent of gas expelled in 1 second as a function of the total amount that can be expelled (the FEV1/FVC ratio) also decreases dramatically. Obstructive disease also produces air trapping, which increases the residual volume, functional residual capacity, and total lung capacity. Reference: Levitzky, pp 34-36, 40-46.

In elderly patients taking benzodiazepines, hypotension is far more likely than an increase in blood pressure. Elderly patients are more prone to the CNS depressant effects of hypnotics; a dose reduction of 50% may still cause excessive sedation with possible ambulatory impairment. Additive CNS depression occurs commonly with drugs used in over- the-counter cold medications, especially antihistamines, and rebound insomnia can occur with abrupt discontinuance of benzodiazepines used as sleeping pills. Alcohol enhances psychomotor depression and the amnestic effects of the benzodiazepines. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Page number 385

While secondary HLH is usually triggered by infection or malignancy, a through medication history is essential for prompt recognition and cessation of potentially offending agents such as lamotrigine. Outcomes for such patients with with holding of offending drug and prompt initiation of dexamethasone treatment. Although most controlled studies have evaluated lamotrigine as add-on therapy, the drug is effective as mono-therapy for focal seizures, and lamotrigine is now widely prescribed for this indication because of its excellent tolerability. It can also improve depression in patients with epilepsy and reduces the risk of relapse in bipolar disorder. Reference: https://jmedicalcasereports.biomedcentral.com/articles/10.1186/s13256-019-2295-1

Ans: B. Change imipramine and haloperidol to fluoxetine and risperidone and add bisacodyl for constipation (Ref Harrison 19/e p1623-1624, 18/e p3531: Goodman Gilman 12/e p410. 1333) Effects of Imipramine: Postural hypotension - Due to alpha blockade by Imipramine & thiazides interaction. Anti-cholinergic side-effect. Hence, Imipramine (TCA) must be discontinued. Should be started on SSRI, fluoxetin & laxative (existing constipation). Effect of haloperidol: Anti-cholinergic side effects. Should start on atypical antipsychotic Risperidone.

Only two of the drugs listed are used for insomnia, eszopiclone and ramelteon. Eszopiclone, zaleplon, and zolpidem are related hypnotics that, though structurally different from benzodiazepines, appear to have a similar mechanism of action. However, unlike benzodiazepines, these drugs are not used in seizures or in muscle spasticity states. Compared with benzodiazepines, the newer hypnotics are less likely to alter sleep patterns. A : Buspirone is not a hypnotic. BUT IT'S ANXIOLYTIC C : Ramelteon activates melatonin receptors in the suprachiasmatic nuclei; flumazenil does not reverse its effects. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Page number. 422

Explanation: Benzodiazepines and barbiturates the two classes of agents, differ markedly in their potencies. Barbiturates act to enhance GABAA receptor function at low micromolar concentrations, while benzodiazepines are considerably more potent, binding with nanomolar affinity. Both benzodiazepines and barbiturates bind to allosteric sites on the GABA-A receptor pentamer and thereby enhance GABA-stimulated Cl-channel function (Statement 4 ruled out) → additive CNS depression with alcohol. Thiopentone has a short duration not due to metabolism, but due to redistribution from brain to peripheral tissues (Statement 3 ruled out) (Thiopentone action) Thiopentone IV → Rapid CNS penetration → Sleep (seconds) → Redistribution to muscle & fat → Recovery Flumazenil is a benzodiazepine antagonist , not effective in barbiturate poisoning (statement 1 Ruled out)

We as doctors should not write any medical abbreviations in our prescription as it creates confusion for the patients. Hence writing the advice in proper English is what is recommended. Alprazolam The primary indication of this potent and intermediate duration of action BZD is anxiety disorder, but it is also being employed as night-time hypnotic due to rapid oral absorption. Its active metabolite has a short half-life. As such, there are few residual effects the next day. Discontinuation after regular use has produced relatively marked withdrawal phenomena.