Which one of the following benzodiazepines has the shortest elimination half-life in the body?
Correct Answer A:
Triazolam has the shortest half-life of any benzodiazepine at 3 hours. Alprazolam (Xanax) has a half life of 12 hours. Lorazepam (Ativan) has a half-life 14 hours. Diazepam (Valium) has a half life of 43 hours.
The mechanism of action of typical antipsychotic drugs is:
Correct Answer B:
Typical antipsychotic medications include haloperidol, chlorpromazine and thioridazine. Their mechanism of action is they block the dopamine (D2) receptors. They treat positive symptoms like hallucination or delusions.
Atypical antipsychotics include risperdione and clozapine. They work by blocking both D2 and serotonin (5-HT) receptors. They treat both positive and negative symptoms.
A 40-year-old patient is on an typical antipsychotic drug. She is started on 20mg once a day. A few weeks later the dose changed to 40mg once daily. She then reports that she has become agitated and aggressive.
The initial proper management of this is:
The following table lists the side effects of antipsychotic drugs:
This patient likely has developed akathisia. Patients with akathisia will be very restless, constantly getting up and then sitting back down, inability to sit still and anxious feelings. This has been caused because of increasing her dose and her dose should be lowered. Initially reduce the dose or the potency of the drug, perhaps considering a newer (atypical) antipsychotic.Additional pharmacologic interventions found to have anti-akathisia effects include beta-adrenergic antagonists (e.g., propranolol), benzodiazepines (e.g., lorazepam), anticholinergics (e.g., benztropine) as well as serotonin antagonists (e.g., cyproheptadine) as an alternative.
A 46-year-old man admitted to the psychiatric ward is given haloperidol. He then develops restlessness. Constantly gets up, then sits back down, and cannot sit still for any period of time.
Which of the following side effects of haloperidol has he developed?
The side effects of antipsychotic medications are as follows:
Parkinsonism: involves tremor, increased muscle tone, bradykinesia or akinesia, drooling, postural instability, loss of spontaneity, micrographia, seborrhea.
Akathisia: motor restlessness accompanied by a feeling of inner restlessness (sometimes described as anxiety), an urge to move, and an inability to sit still, patients may pace or continuously move their feet and legs.
Dystonia: sustained contraction of muscles, twisting postures and may be visible only when the patient is moving. Neck and arm muscles are most commonly affected.
Tardive dyskinesia: hyperkinesia, involuntary body movements most often of the muscles of the face, mouth, and tongue.
A patient was diagnosed by a psychiatrist as a case of depression and was prescribed an antidepressant for 8 months. Now, you are the family physician to see him and the symptoms have already been subsided completely.
Which of the following should you not do?
In order to avoid antidepressant withdrawal symptoms, never stop the medication “cold turkey.” Instead, gradually taper the dose, allowing for at least 1-2 weeks between each dosage reduction. This tapering process may take up to several months, and should be monitored.
If there is a recurrence of depression or severe discontinuation symptoms, patient should go back to a higher dose and withdraw more slowly.
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