Pharmacology and Pain Control Flashcards

A 58-year-old male patient with a history of gastric ulcers and mild renal insufficiency requires extraction of a severely decayed mandibular molar. Which of the following analgesic regimens is most appropriate for managing his postoperative pain?

Answer: Acetaminophen 650 mg every 6 hours

Acetaminophen is the most appropriate choice because it is an effective analgesic that works centrally and lacks the gastrointestinal and renal side effects associated with NSAIDs. Ibuprofen and Naproxen are NSAIDs, which are contraindicated in patients with a history of gastric ulcers and renal insufficiency due to their inhibition of prostaglandins that protect the GI mucosa and maintain renal perfusion. Opioids like oxycodone should be reserved for severe pain where non-opioids are insufficient, and they carry risks of dependence and other side effects.

A dentist administers 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. How many milligrams of lidocaine and epinephrine did the patient receive?

Answer: 36 mg lidocaine and 0.018 mg epinephrine

A 2% lidocaine solution contains 20 mg of lidocaine per mL. Therefore, a 1.8 mL cartridge contains 20 mg/mL * 1.8 mL = 36 mg of lidocaine. A 1:100,000 epinephrine concentration means there is 1 gram of epinephrine in 100,000 mL of solution, which is equivalent to 1000 mg in 100,000 mL, or 0.01 mg per mL. For a 1.8 mL cartridge, the total epinephrine is 0.01 mg/mL * 1.8 mL = 0.018 mg.

Which of the following best describes the primary mechanism of action of nonsteroidal anti-inflammatory drugs (NSAIDs) in managing dental pain?

Answer: Inhibiting the cyclooxygenase (COX) enzymes

NSAIDs exert their analgesic, anti-inflammatory, and antipyretic effects primarily by inhibiting the cyclooxygenase (COX) enzymes (both COX-1 and COX-2). This action blocks the conversion of arachidonic acid into prostaglandins, which are key mediators of pain and inflammation. Opioids bind to mu-receptors, local anesthetics block sodium channels, and benzodiazepines potentiate GABA.

A 25-year-old female patient presents for a restorative procedure. She reports an allergy to 'Novocain' from a past dental experience where she developed a rash. Which local anesthetic would be the safest to use for this patient?

Answer: Articaine

Novocain is the brand name for procaine, which is an ester-type local anesthetic. True allergic reactions to local anesthetics are rare, but when they occur, they are more common with the ester class due to the metabolite para-aminobenzoic acid (PABA). Articaine is an amide-type local anesthetic. Cross-allergenicity between ester and amide anesthetics is unlikely. Therefore, an amide anesthetic like articaine (or lidocaine, mepivacaine) would be a safe alternative. Benzocaine and tetracaine are also esters.

According to CDC and ADA guidelines, which of the following is considered the first-line therapy for managing acute dental pain, such as after a routine extraction?

Answer: A combination of an NSAID and acetaminophen

Current guidelines from the CDC and ADA recommend a multimodal approach, prioritizing non-opioid analgesics as first-line therapy for acute dental pain. The combination of an NSAID (like ibuprofen) and acetaminophen has been shown to be highly effective, often more so than opioids, for managing dental pain due to their different mechanisms of action (peripheral vs. central). Opioids should only be considered when non-opioid therapies are insufficient or contraindicated.

A patient is prescribed an opioid analgesic after a complex surgical extraction. Which of the following concurrent medications would represent the most significant risk for life-threatening respiratory depression?

Answer: Diazepam

The concurrent use of opioids and benzodiazepines, such as diazepam, significantly increases the risk of severe central nervous system and respiratory depression, which can be fatal. This is a black box warning for both classes of drugs. Lisinopril (ACE inhibitor), Metformin (antidiabetic), and Atorvastatin (statin) do not have this direct synergistic effect on respiratory depression when combined with opioids.