Sedation for an anxious smoker

Correct answer: A. His complete nasal obstruction

• A. CORRECT. Nitrous oxide is delivered through a NASAL HOOD. If the patient cannot breathe through the nose the technique simply cannot work, and attempting it risks inadequate sedation and hypoxia. NASAL OBSTRUCTION is an ABSOLUTE contraindication, and an active upper respiratory tract infection is a clear reason to defer. The other respiratory considerations are RELATIVE: COPD, where the hypoxic respiratory drive matters and high inspired oxygen can be hazardous; severe asthma; and pneumonia.
• B. Repeated exposures LESS THAN ONE WEEK apart are a relative contraindication, because nitrous oxide inactivates methionine synthase by oxidising vitamin B12 and repeated close exposure can cause bone marrow suppression. Two months is far outside that window and is irrelevant.
• C. Anxiety is the INDICATION, not a contraindication — mild to moderate apprehension, the frightened child, gagging, and reducing awareness of time are exactly what nitrous oxide is for. Note the twist, though: SEVERE apprehension is a relative contraindication, because a highly anxious patient often cannot tolerate the mask and needs a different technique.
• D. Smoking itself is not a contraindication. The chronic respiratory disease that may accompany it can be.

Note: ABSOLUTE contraindications to memorise: nasal obstruction, complete inability to communicate (disability or language), raised intracranial pressure, use as a substitute for adequate local or general anaesthesia, patient refusal, active or recovering substance abuse, and lack of adequate gas scavenging. RELATIVE: pulmonary disease, respiratory infection, first-trimester pregnancy, psychiatric illness, immunocompromise, multiple sclerosis, blocked middle ear, current cannabis or hallucinogen use, severe apprehension, and repeated exposures under a week apart.

Correct answer: A. Bupropion

• A. CORRECT. BUPROPION — marketed as Zyban for cessation and as Wellbutrin as an antidepressant — is a noradrenaline and dopamine reuptake inhibitor. Serious NEUROPSYCHIATRIC EVENTS have been reported in patients taking it for smoking cessation: depression, suicidal ideation, suicide attempt and completed suicide. As an antidepressant it carries a boxed warning for suicidality in children, adolescents and young adults up to age 24. It also LOWERS THE SEIZURE THRESHOLD in a dose-dependent way, which makes it contraindicated in seizure disorders, in bulimia and anorexia nervosa, and in abrupt alcohol or benzodiazepine withdrawal — directly relevant to this patient's seizure history.
• B. Nasal spray delivers nicotine fastest of the replacement forms and is the most locally irritating, causing nasal and throat burning, but it does not carry bupropion's psychiatric profile.
• C. Nicotine patches deliver a slow, steady dose and are a nicotine agonist without those central effects. Their characteristic complaints are local skin reaction and vivid dreams if worn overnight.
• D. Lozenges and gum cause hiccups, dyspepsia and jaw ache. The dental instruction for nicotine gum is worth knowing: CHEW AND PARK rather than chew continuously, and avoid acidic drinks beforehand since they reduce absorption.

Note: Note the contrast with VARENICLINE, the other non-nicotine agent. It carried a similar boxed neuropsychiatric warning, which the FDA REMOVED in 2016 after the EAGLES trial found no significant excess risk. Bupropion's warning language for cessation use remains in place. Depressed mood is also a genuine symptom of nicotine withdrawal itself, which complicates attributing these events to the drug.