CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 6, July 2012
352
AFRICA
‘Gabapentin works, despite a host
of side effects including dizziness,
somnolence and peripheral oedema.
Pregabalin is effective, but it is essential
to use a therapeutically adequate twice-
daily dose, between 75 and 150 mg bid’,
Dr Raff noted.
Duloxetine at a dosage of 60 mg
daily is the recommended dose and there
is more evidence for its use in painful
diabetic neuropathy (PDN) than there is
for venlafaxine use.
Oxycodone in controlled-release
format is now available in South Africa.
‘It can however take up to four weeks
to provide pain relief and patients must
be prepared for this treatment delay’, he
noted. ‘Tramadol has adequate but not
large studies supporting its third-line use.’
The therapeutic rationale for post-
herpetic neuralgia (PHN) is treatment
with gabapentin, pregabalin, TCAs, and
strong opioids as they have evidence of
efficacy for PHN. The first-, second- and
third-line therapy is therefore essentially
the same for PNP and DPN.
Trigeminal neuralgia therapy options
are sparse with only carbamazepine
and oxcarbazepine achieving positive
outcomes.
Therapy for central neuropathic
pain from spinal cord injuries and
stroke is a neglected field with few
clinical trials. South African guidelines
suggest carbamazepine, pregabalin or
amitryptiline but note that there is limited
supporting evidence in this category of
patients.
‘Non-pharmacological treatments, if
they work for the patient, should be
positively regarded by the attending
physician’, Dr Raff concluded.
New South African guidelines for the
management of neuropathic pain are
available on the
South African Medical
Journal
website:www.samj.org.za/index.
php/smj/article/download/5472/4036.
Julia Aalbers
1.
Dickenson AH,
et al
. Pharmacological treat-
ment of peripheral neuropathic pain condi-
tions based on shared commonalities despite
multiple aetiologies.
Pain
2005;
113
(3):
251–254.
2.
Ahal N,
et al
. EFNS guidelines on the
Pharmacological treatment of neuropathic
pain. 2010 revision.
Eur J Neurol
2010;
17
:
1113–e88.
3.
Chetty S, Baalbergen E, Bhigjee AI,
Kamerman P, Ouma J,
et al.
Clinical prac-
tice guidelines from management of neuro-
pathic pain: expert panel recommendations
for South Africa.
S Afr Med J
2012;
102
(5):
312–325.
TABLE 2. SUMMARY OF THERAPEUTICAGENTS FOR PERIPHERALAND DIABETIC NEUROPATHY IN SOUTHAFRICA
Contraindications/precautions/drug interactions
Other benefits
α
2
δ
-ligands
Pregabalin
No significant drug interactions
Linear pharmacokinetics
Dose reduction required in renal insufficiency
Improvement of
sleep disturbance
Anxiolytic
Gabapentin Dosage reduction required in renal insufficiency
No clinically significant drug interactions
Improvement of
sleep disturbance
SNRIs
Duloxetine
Contraindicated in severe hepatic impairment, end-stage renal disease, alcohol abuse, concomitant use of tramadol and
MAOIs
Low initial doses for mild to moderate hepatic and renal impairment
Caution required in patients with history of mania, seizures, acute narrow-angle glaucoma
Glucose monitoring required as worsening glycaemic control seen in diabetic patients
Drug interactions with tramadol, TCAs, SSRIs and SNRIs. Inhibition of metabolism of drugs metabolised by CYP2D6
Suicide risk (black-box warning, in line with other antidepressants)
Improvement of
major depression
disorder and
generalised
anxiety disorder
Venlafaxine Caution required in patients with cardiac disease
Risk of hypertension, hence regular blood pressure monitoring required
Lower dose may be necessary in patients with renal impairment (GFR = 10–70 ml/min) or cirrhosis of the liver
Use with caution in patients with history of seizures and history of mania
Drug interactions with tramadol, TCAs, SSRIs and SNRIs. Inhibition of metabolism of drugs metabolised by CYP2D6
Suicide risk (black-box warning, in line with other antidepressants)
TCA:
amitriptyline
Contraindicated with MAOI use, antihypertensives, patients with myocardial infarction/heart block, untreated narrow-
angle glaucoma
Use with caution in patients with glaucoma, cardiovascular disease, especially in elderly patients, hyperthyroidism,
impaired liver function, epilepsy, urinary retention, prostatic hypertrophy, constipation, mania
Improvement of
major depression
disorder
Tramadol
High risk of addiction and abuse, psychomotor impairment possible
Use with caution in patients with history of substance abuse, suicide risk, seizure disorder and in elderly patients
because of risk of confusion
Contraindicated with concomitant use of SSRI, SNRI, TCA
Rapid onset of
analgesic benefit
Strong
opioids
High risk of addiction and abuse, psychomotor impairment possible
Use with caution in patients with history of substance abuse, suicide risk and in elderly patients because of risk of
confusion
Contraindicated with concomitant use of SSRI, SNRI, TCA
Rapid onset of
analgesic benefit
SNRIs = serotonin–noradrenalin reuptake inhibitors; MOAIs = monoamine oxidase inhibitors; TCAs = tricyclic antidepressants; SSRIs = selective
serotonin reuptake inhibitors.
