A nurse is preparing to administer valproic acid 500 mg PO. Available is valproic acid oral solution 250 mg/5 mL. How many mL should the nurse administer?
(Round the answer to the nearest whole number.)

The correct answer is Choice B

Choice A rationale: Dantrolene is a direct-acting skeletal muscle relaxant that works by inhibiting calcium release from the sarcoplasmic reticulum in muscle cells, thereby reducing muscle contraction. It is not intended for as-needed use during acute spasms but requires consistent dosing to maintain therapeutic levels. Intermittent use undermines its pharmacokinetics and may lead to subtherapeutic effects. The half-life of dantrolene is approximately 8.7 hours, and steady-state levels are necessary for optimal spasticity control in multiple sclerosis.

Choice B rationale: Dantrolene’s therapeutic effect on muscle spasticity may take several weeks to manifest due to its mechanism of action involving gradual reduction in intracellular calcium availability. If no improvement is noted within 3 months, it may indicate inadequate response or the need for dosage adjustment. Monitoring for efficacy is essential, as prolonged use without benefit increases risk of hepatotoxicity. Liver function tests should be monitored regularly. Normal ALT levels are 7–56 units/L; elevations may signal toxicity.

Choice C rationale: Dantrolene is classified as pregnancy category C, indicating that risk to the fetus cannot be ruled out. Animal studies have shown adverse effects, and there are no adequate human studies confirming safety during pregnancy. Therefore, it is not considered safe without careful risk-benefit analysis. Teratogenicity and fetal toxicity are concerns due to its action on muscle fibers and potential systemic effects. Pregnant clients should consult their provider before initiating or continuing dantrolene therapy.

Choice D rationale: Dantrolene does not directly affect calcium levels in the bloodstream. Its mechanism involves inhibition of calcium release within muscle cells, not systemic calcium metabolism. Routine calcium monitoring is not required unless the client has a separate condition affecting calcium homeostasis. Normal serum calcium levels range from 8.5 to 10.5 mg/dL. The primary lab concern with dantrolene is hepatotoxicity, necessitating regular liver function tests, not calcium surveillance. This statement reflects a misunderstanding of the drug’s effects.

Choice A rationale:

Pseudoparkinsonism mimics the symptoms of Parkinson’s disease but is not typically characterized by choreiform movements, lip smacking, and spastic facial distortions.

Choice B rationale:

Tardive dyskinesia, a potential side effect of long-term use of chlorpromazine, is characterized by involuntary movements such as lip smacking and facial distortions.

Choice C rationale:

Akathisia is characterized by a sense of restlessness and a compulsion to move, not typically by the symptoms described.

Choice D rationale:

Dystonia involves involuntary muscle contractions and distortions but not typically the specific symptoms described.

So, the correct answer is B.