Pharmacological management of neuropathic pain in patients with vestibular schwannomas: Experience of the Atlantic Lateral Skull Base Clinic

Table 1 Summary of drugs used for management of trigeminal neuralgia and neuropathic pain

Drug	Action	Dosing	Common side effects1
CBZ	Blocks Na+ and Ca2+ channels	300-1000 mg; 100 mg BID initially, increase by 200 mg weekly Adequate trial 8-12 wk, 2 wk at maximal dose	Drowsiness, ataxia, headaches, nausea, vomiting, constipation, blurred vision, rash Drug interactions Taper doses when discontinuing
OXC	Keto derivative of CBZ, same actions	Equivalent efficacy to CBZ; 300-2400 mg; 300 mg BID initially, increase by 600 mg weekly Adequate trial 8-12 wk, 2 wk at maximal dose	Improved tolerability compared to CBZ Vertigo, fatigue, dizziness, nausea, hyponatraemia in high doses No major drug interactions Taper doses when discontinuing
TCAs or tricyclic antidepressants: nortriptyline, amitriptyline	Block NA and 5-HT reuptake, block Na+ channels, interact with several neurotransmitter systems	Nortriptyline 10 mg (elderly) or 25 mg (adult) at bedtime; increase dose by 10 or 25 mg every 3-7 d; up to 75-100 mg daily Adequate trial 6-8 wk, 2 wk at maximal dose Amitriptyline doses similar	Nortriptyline is better tolerated than amitriptyline Dry mouth, constipation, blurred vision, sedation, orthostatic hypotension Taper doses when discontinuing
SNRIs or serotonin-noradrenaline reuptake inhibitors: Duloxetine, Venlafaxine	Similar actions to TCAs, but fewer interactions with receptor systems	Duloxetine: 60 mg/d, increase to 120 mg after 1 wk Venlafaxine: 75 mg/d, increase to 225 mg over 3 wk Adequate trial 4-6 wk, 2 wk at maximum dose	Headache, nausea, dry mouth, sleepiness, fatigue, constipation, dizziness, decreased appetite, and increased sweating. Taper doses when discontinuing Drowsiness, dizziness, weakness, feeling nervous, tinnitus, increased sweating, blurred vision, dry mouth, changes in appetite or weight, facial flushing, mild nausea, constipation, sexual side-effects Taper doses over 7-10 d when discontinuing
Gabapentin	Ca2+ channel modulator	100-300 mg TID, increase dose every 1-7 d; maximum dose 3600 mg daily Adequate trial 3-8 wk titration, 2-8 wk at maximal dose	Dizziness, sedation, weight gain, weakness, tiredness, nausea, diarrhea, constipation, blurred vision, headache, breast swelling, dry mouth, fatigue, myalgia, loss of balance or coordination Taper doses when discontinuing
Pregabalin	Ca2+ channel modulator	50 mg OD or 25 mg BID, double dose each week; maximum daily dose 600 mg Adequate trial is 4 wk at maximal dose	Dizziness, drowsiness, loss of balance or coordination, problems with memory or concentration, anxiety, depersonalization, hypertonia, hypesthesia, decreased libido, nystagmus, paresthesia, twitching, breast swelling, tremors, dry mouth, constipation Taper doses when discontinuing (minimum of one week)
Tramadol	Inhibits NA and 5-HT reuptake, binds opioid receptors	50 mg BID, increase by 50-100 mg daily in divided doses over 3-7 d as tolerated; 400 mg is maximum dose (300 mg in elderly) Adequate trial is 4 wk at maximum dose	Dizziness, spinning sensation, constipation, upset stomach, headache, drowsiness, feeling nervous or anxious
Morphine	Interacts with mu opioid receptors in spinal cord and brain, regulates synaptic activity in pain pathways	10-15 mg q4h or prn (equianalgesic doses for other opioids); after 1-2 wk, convert to long-acting opioid (e.g., CR hydromorphone) Titration allows for dose escalation Adequate trial is 4-6 wk	Sedation, pruritus, constipation, diarrhea, weight loss, nausea, vomiting, stomach pain, loss of appetite, flushing (warmth, redness, tingling), headache, dizziness, spinning sensation, memory problems, sleep problems (insomnia), strange dreams Taper doses when discontinuing

¹These are not a complete list of side effects and others may occur. CBZ: Carbamazepine; 5-HT: Serotonin; NA: Noradrenaline; OXC: Oxcarbazepine; q4h: Every four hours; BID: Twice a day; TCA: Tricyclic antidepressant; SNRI: Serotonin-norepinephrine reuptake inhibitors; prn: Pro re nata; TID: Three times a day; OD: Once daily; CR: Continuous release.