Atypical Odontalgia: A Review of the Literature

Marcello Melis, DDS, RPharm; Silvia Lobo Lobo, DDS, MS; Caroline Ceneviz, DDS; Khalid Zawawi, BDS; Emad Al-Badawi, BDS, MS; George Maloney, DMD; Noshir Mehta, DMD, MDS, MS

Disclosures

Headache. 2003;43(10) 

In This Article

Treatment

Once the diagnosis of AO has been made, appropriate treatment needs to be established avoiding any further dental procedure that could only aggravate the pain. Most of the medications that are used are formulated for the treatment of neuropathic pain and seem to be effective in the majority of patients with AO.

In many of the articles reviewed,[4,5,8,9,13,16,21,23,24,26,76,83,84] tricyclic antidepressants have been prescribed with good results, alone or in association with phenothiazines (perphenazine or trifluoperazine).[4,9,21,24,26,83] More than their action on the mood, their analgesic effect seems to be responsible for the clinical results,[16,23] and phenothiazines potentiate the analgesic effect of the antidepressant. Amitriptyline has been used more frequently, in doses starting from 25 mg and going up to 100 mg daily.[2,4,5,8,9,16,21,23,24,83,84] Other tricyclics that have been suggested are imipramine,[4,21,83] nortriptyline,[21,84] and dothiepen.[11] What limits the use of these medications is the occurrence of side effects. Tricyclics may cause dry mouth, weight gain, constipation, and urinary retention, and are contraindicated in patients with angle-closure glaucoma or high intraocular pressure and in patients taking other medications such as monoamine oxidase (MAO) inhibitors, CNS depressants (alcohol, barbiturates, narcotics), anticholinergics, and sympathomimetics, because of drug-to-drug interactions. It is usually possible to avoid or minimize the side effects by adjusting the dose, or switching to a different medication within the same category (eg, nortriptyline has less anticholinergic effect compared to amitriptyline and imipramine).[4,83,85] Phenothiazines need to be used more carefully because of potentially permanent adverse effects in the nervous system causing tardive dyskinesia. For this reason, when possible, their use should be limited and once the symptoms subside, the clinician should try to taper and stop the medication. Other side effects include drowsiness, dizziness, skin reactions, rash, dry mouth, insomnia, amenorrhea, fatigue, muscular weakness, anorexia, endocrine disturbance, blurred vision, and neuromuscular reactions; also, phenothiazines interfere with vasopressors, oral anticoagulants, thiazide, anticonvulsants, and CNS depressants.[4,83,86]

Some results have been reported with other medications such as gabapentin,[26] clonazepam,[24,26,76] baclofen,[24,26,76] doxepin,[4,8] α- and β-blockers,[76] aspirin,[9] phentolamine infusion,[14] cocaine,[24,26] and MAO inhibitors,[11,13,24] especially in cases where tricyclic antidepressants were not tolerated. Opioid narcotic analgesics (oxycodone, meperidine, controlled-release morphine, fentanyl, ketamine, and methadone) have been tried, but they are usually only moderately effective for neuropathic pain and AO.[24,26]

Sometimes a more "peripheral" intervention can give relief, especially when the local component of the pain is significant. Injections of local anesthetics and corticosteroids (dexamethasone), eventually repeated more than once, have been found effective especially in early treatments;[24,26] sympathetic and parasympathetic nerve blocks, through the stellate or sphenopalatine ganglia, have been reported with similar results.[9,76]

Medications applied topically to the site of the pain sometimes give good results, such as capsaicin at the concentration of 0.025% for 4 weeks, eventually associated with a topical anesthetic if the treatment is too painful,[14,23] and eutectic mixture of lidocaine and prilocaine bases (EMLA) cream at the concentration of 5%.[14]

Based on the results, once the diagnosis is made, we recommend starting treatment with low doses of amitriptyline (20 to 25 mg) or another tricyclic antidepressant if side effects are tolerable, and slowly titrate the dose evaluating effect on pain and side effects of the medication. Addition of phenothiazines should be avoided if not needed. If pain relief is obtained, the dose of the drug should be progressively reduced and finally discontinued, unless the symptoms return during the taper. In this case, the patient should be administered the lowest dose of medicine sufficient to control the pain.

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