This case report describes a 49-year-old woman with a five-year history of persistent Trichomonas vaginalis infection that was recalcitrant to treatment with several courses of metronidazole and tinidazole. A single course of intravaginal paromomycin tablets cleared the infection, despite the patient stopping treatment after 10 days due to vaginal soreness and becoming asymptomatic within three weeks. Paromomycin is an alternative treatment for recalcitrant T. vaginalis infections when standard therapies have failed.

1. CASE REPORT
Paromomycin treatment of recalcitrant Trichomonas vaginalis
S C Tayal MD FRCP FRCPI*, S A Ochogwu MBBS DTM&H FAGP* and H Bunce B.Pharm DipClinPharm†
*Department of Genito-Urinary Medicine; †Department of Pharmacy, The James Cook University Hospital, Middlesbrough, TS4 3BW, UK
Summary: We report a 49-year-old woman with a five-year history of persistent Trichomonas vaginalis infection. Treatment with
several courses of metronidazole and tinidazole failed to resolve her symptoms. A single course of intravaginal paromomycin was
effective in clearing the infection.
Keywords: paromomycin, treatment, recalcitrant, Trichomonas vaginalis
INTRODUCTION was not working for her and she no longer wanted male
doctors to see her. She had to be counselled by the health
Trichomonas vaginalis is a protozoan sexually transmitted infec-
adviser before accepting to see a male doctor again. It was
tion easily treatable with metronidazole or tinidazole. It is the
explained to her that paromomycin, unlicensed in the UK,
most common pathogenic protozoan infection affecting
would be prescribed for her in view of her persistent infection.
humans in industrialized countries. The World Health
The pharmacist was unable to obtain pessaries and it was
Organization estimates 180 million cases per year worldwide.1
agreed to use oral tablets intravaginally. On her eighth visit
Treatment failure with these agents is on the increase and
which was 13 months after her first visit, she was given a
studies have shown that at least 5% of clinical cases of T. vagi-
two-week course of intravaginal tablets of (Gabbroralw) paro-
nalis are caused by strains resistant to metronidazole.2 The
momycin 250 mg twice a day and the side-effects were
current UK national guideline lists alternative agents but
explained to her. The patient became asymptomatic within
when they fail, there is no effective recommended treatment.3
three weeks after commencing paromomycin, despite stopping
Paromomycin is not yet licensed for use in the treatment of
the treatment after 10 days because of vaginal soreness. During
T. vaginalis, but it has been successfully used in some recalci-
her next visit she developed urinary tract infection, which was
trant infections. Side-effects are its major drawback. The treat-
treated with a three-day course of cefalexin 500 mg twice daily.
ment of choice for T. vaginalis remains metronidazole.
The patient remains asymptomatic and tests of cure performed
during subsequent visits revealed complete clearance of
CASE REPORT T. vaginalis.
A 49-year-old woman was referred to the genitourinary clinic
by her general practitioner, with a five-year history of persistent DISCUSSION
T. vaginalis infection. She was not sexually active and her last Paromomycin is an aminoglycoside antibiotic with a spectrum
sexual intercourse was several years prior to attendance. Past of activity against some protozoa. It is available for treatment
medical history revealed numerous weekly courses of metroni- of leishmaniasis on named-patient basis from IDIS. It is not
dazole 400 mg twice per day. She was asymptomatic and licensed for use in the treatment of T. vaginalis. Case reports
neither T. vaginalis nor any sexually transmitted infection was have shown that persistent or recalcitrant T. vaginalis infections
diagnosed on the first visit. She was seen again about 10 have been treated successfully with paromomycin.4 It has the
months later. This time she presented with symptoms and side-effect of pain and mild to severe mucosal ulceration,
T. vaginalis was diagnosed both on wet mount and culture. which makes its routine clinical use unlikely.5 Nitroimidazole
Over the next three months, she received a week course of resistance was first reported in 1978 and since then many recal-
metronidazole 400 mg twice a day, clotrimazole (Canestenw) citrant cases of T. vaginalis have been reported. Resistance
pessary 500 mg stat, metronidazole 2 g stat, fluconazole testing is not available in the UK. Increasing the dose of metro-
150 mg stat, and a week course of erythromycin 250 mg four nidazole may overcome resistance, indicating that resistance to
times a day. She also received a week course of tinidazole the medication is relative but higher and sometimes toxic doses
2 gm twice a day and chlorphenamine 4 mg as necessary. of metronidazole cause intolerable side-effects.2,6
She remained symptomatic and T. vaginalis continued to be
diagnosed on wet mount and culture. At this stage, the
patient became frustrated and irritated because the treatment CONCLUSION
The use of paromomycin in the treatment of recalcitrant T. vagi-
Correspondence to: Dr S C Tayal
nalis infection is one option available to clinicians. Our experi-
Email: sarup.tayal@stees.nhs.uk
ence in this patient shows that it is not only cost-saving, but
DOI: 10.1258/ijsa.2009.009085. International Journal of STD & AIDS 2010; 21: 217 –218

2. 218 International Journal of STD & AIDS Volume 21 March 2010
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reduces the psychological impact of a recalcitrant disease. Its 3 Clinical Effectiveness Group (British Association for Sexual Health
use is however limited by its side-effects and not all patients and HIV). UK National Guideline on management of trichomonas
vaginalis. 2001
experience success with paromomycin treatment. 4 Nyirjesty P, Weitz MV, Gelone SP, et al. Paromomycin for
nitroimidazole-resistant trichomonosis. Lancet 1995;346:1110
5 Poppe WA. Nitro-imidazole resistant vaginal trichomoniasis vaginalis treated
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