Direct-Acting Antispasmodics Pharmacodynamics

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How does dantrolene cause muscle relaxation?

By increasing the release of calcium in slow muscle fibers

By inhibiting acetylcholine release

By interfering with the release of calcium from the sarcoplasmic reticulum (correct)

By blocking neuromuscular transmission

What is the unique characteristic of botulinum toxin type A's action when injected into the detrusor muscle?

It inhibits acetylcholine release (correct)

It affects the sweat glands

It blocks neuromuscular transmission

It causes muscle relaxation

Which condition is dantrolene mainly used to treat?

Localized muscle reduction

Dermatological conditions

Spasticity associated with upper neuron disorders (correct)

Neuromuscular disorders

What is the primary pharmacodynamic effect of botulinum toxin type A when injected intradermally?

Temporary denervation of sweat glands Signup and view all the answers

What effect does botulinum toxin type A have on neuromuscular transmission?

Blocks it by binding to receptor sites on motor or sympathetic nerves Signup and view all the answers

What is the half-life of dantrolene after a 100 mg dose?

8.7 hours Signup and view all the answers

What is the primary concern with prescribing mixed agonist-antagonists for narcotic-addicted individuals?

Risk of physical withdrawal Signup and view all the answers

Why is careful titration of opioid antagonists required?

To prevent acute abstinence syndrome Signup and view all the answers

Which of the following is a key concern with the use of codeine in children and adolescents?

Increased risk of respiratory depression Signup and view all the answers

What is the primary route of excretion for the opioid analgesics and antagonists listed in the table?

Urine Signup and view all the answers

What is the potential risk for lactating women who are ultrametabolizers of codeine?

Increased risk of respiratory depression in their infants Signup and view all the answers

Which of the following opioid analgesics has the fastest onset of action?

Sufentanil Signup and view all the answers

What is the primary route of excretion for dantrolene?

Urine Signup and view all the answers

What is the primary contraindication for the use of dantrolene?

Active liver disease Signup and view all the answers

Which of the following adverse effects is most commonly associated with dantrolene administration?

Central nervous system effects Signup and view all the answers

What is the primary risk factor for fatal hepatotoxicity associated with dantrolene?

Female sex Signup and view all the answers

What is the primary mechanism by which botulinum toxin type A can produce systemic effects?

Spread from the site of injection Signup and view all the answers

What is the primary treatment for botulinum toxin type A overdose?

Administration of an antitoxin Signup and view all the answers

What is the primary contraindication for the use of botulinum toxin type A for bladder dysfunction?

Urinary tract infection Signup and view all the answers

What is the primary adverse effect associated with the use of botulinum toxin type A for chronic migraine treatment?

Neck pain Signup and view all the answers

What is the primary drug interaction concern with the concomitant use of dantrolene and calcium channel blockers?

Ventricular fibrillation and cardiovascular collapse Signup and view all the answers

What is the primary mechanism by which aminoglycosides and anticholinergic drugs can potentiate the effects of botulinum toxin type A?

Synergistic inhibition of neuromuscular transmission Signup and view all the answers

What is the primary receptor associated with the analgesic (pain-relieving) effects of opioids?

Mu receptor Signup and view all the answers

Which of the following is NOT a mixed agonist-antagonist opioid?

Buprenorphine Signup and view all the answers

Which of the following adverse effects is associated with the activation of delta and sigma receptors?

Dysphoria and hallucinations Signup and view all the answers

What is the primary mechanism of action of opioid analgesics in producing analgesia?

Inhibiting adenylyl cyclase activity Signup and view all the answers

What is the primary mechanism of action of opioid antagonists in reversing the effects of opioids?

Blocking opioid receptor sites Signup and view all the answers

What is the typical half-life range for most opioid analgesics?

6 to 12 hours Signup and view all the answers

Which of the following is a contraindication for the use of opioid analgesics?

Acute abdominal conditions Signup and view all the answers

What is the primary route of metabolism for opioid analgesics and antagonists?

Hepatic metabolism Signup and view all the answers

What is the potential risk associated with the use of opioids in infants and children?

Increased risk of respiratory depression Signup and view all the answers

What is the primary mechanism of action of Suboxone (a combination of buprenorphine and naloxone)?

Buprenorphine is a partial agonist, and naloxone is an antagonist Signup and view all the answers

What is the maximum daily dose of dantrolene for adult patients?

100 mg four times a day Signup and view all the answers

What is the recommended starting dose of dantrolene for children older than age 5?

0.5 mg/kg daily Signup and view all the answers

What is the recommended dose of dantrolene for treating a malignant hyperthermia crisis?

Both a and b Signup and view all the answers

What is the reason for not administering a second dose of botulinum toxin until the effects of the first dose resolve?

To prevent excessive neuromuscular weakness Signup and view all the answers

What is the primary monitoring parameter for patients taking dantrolene?

Decreased spasticity Signup and view all the answers

What is the primary adverse effect that requires stopping and restarting dantrolene?

Diarrhea Signup and view all the answers

What is the primary adverse effect that patients should be warned about with botulinum toxin type A (Botox) injections?

Respiratory paralysis and swallowing problems Signup and view all the answers

Which of the following is a mixed agonist-antagonist opioid analgesic?

None of the above Signup and view all the answers

Which of the following is an opioid antagonist?

All of the above Signup and view all the answers

What is the primary reason for using opioid analgesics?

To alter the perception of and response to painful stimuli Signup and view all the answers