ATI RN
Central and Peripheral Nervous System Drugs Questions
Question 1 of 5
Which of the following structures was most likely the site of therapeutic action of botulinum toxin injected into the ocular muscles of the 22-year-old man with strabismus?
Correct Answer: B
Rationale: The correct answer is B: Somatic nerve terminals. Botulinum toxin acts by inhibiting the release of acetylcholine at the neuromuscular junction, leading to muscle paralysis. In the context of ocular muscles in strabismus, the toxin would target the somatic nerve terminals that innervate the extraocular muscles. This action results in the relaxation of the affected muscle, helping to correct the misalignment of the eyes. Choices A, C, and D are incorrect as they do not directly relate to the mechanism of action of botulinum toxin at the neuromuscular junction.
Question 2 of 5
Which of the following adverse effects was most likely to occur in the patient receiving local injections of botulinum toxin for benign essential blepharospasm?
Correct Answer: D
Rationale: The correct answer is D: Eyelid ptosis. Botulinum toxin injections can weaken the muscles, leading to eyelid ptosis (drooping). This is a common adverse effect seen in patients receiving these injections for benign essential blepharospasm. Other choices are incorrect: A, retinal detachment, is not associated with botulinum toxin injections; B, visual hallucinations, are not a common side effect; C, visual loss, is not a typical adverse effect of botulinum toxin injections for blepharospasm.
Question 3 of 5
This drug is effective in all forms of epilepsy in all age groups.
Correct Answer: B
Rationale: The correct answer is B: Carbamazepine. Carbamazepine is a broad-spectrum antiepileptic drug effective in various forms of epilepsy across all age groups. It works by stabilizing neuronal membranes and reducing repetitive firing of neurons. Acetazolamide (A) is a diuretic used for certain types of seizures. Ethosuximide (C) is mainly used for absence seizures. Felbamate (D) is reserved for refractory epilepsy cases due to its potential serious side effects. Therefore, Carbamazepine is the best choice for treating epilepsy across different forms and age groups.
Question 4 of 5
Which of the following drugs was most likely prescribed?
Correct Answer: A
Rationale: The correct answer is A: Levetiracetam. Levetiracetam is a commonly prescribed antiepileptic drug due to its broad spectrum of activity and favorable side effect profile. It is often used as a first-line treatment for various types of seizures. Carbamazepine, valproic acid, and phenobarbital are also antiepileptic drugs, but Levetiracetam is preferred in many cases due to its lower potential for drug interactions and side effects. Therefore, based on the information provided, Levetiracetam is the most likely drug to be prescribed in this scenario.
Question 5 of 5
A 54-year-old woman with a previously well-controlled seizure disorder was brought to the hospital because of recurrent, generalized tonic-clonic seizures. The patient was intubated and mechanically ventilated. She was treated with intravenous diazepam and fosphenytoin but continued to exhibit intermittent seizures and did not regain consciousness between them. A diagnosis of refractory status epilepticus was made. A large dose of which of the following drugs would be appropriate to add to the patient's therapy at this time?
Correct Answer: C
Rationale: The correct answer is C: Valproic acid. Valproic acid is a broad-spectrum antiepileptic drug effective in treating refractory status epilepticus. It acts on multiple mechanisms, making it suitable for cases not responding to first-line treatments. Diazepam (A) is already being used, and adding more might not be effective. Ethosuximide (B) is indicated for absence seizures, not generalized tonic-clonic seizures. Carbamazepine (D) is ineffective in treating status epilepticus.