Influence of Trimethoprim-Sulfamethoxazole for the Recurrence of Ocular Toxoplasmosis

Condition(s) targeted: Ocular Toxoplasmosis

Intervention: Trimethoprim-Sulfamethoxazole (Drug)

Phase: Phase 3

Status: Recruiting

Sponsored by: University of Campinas, Brazil

Official(s) and/or principal investigator(s):
Rodrigo PC Lira, PhD, Principal Investigator, Affiliation: University of Campinas

Overall contact:
João Paulo F. Felix, Phone: 19 3521 7396, Email: joaopaulofelix@hotmail.com

The protozoan Toxoplasma gondii is an obligate intracellular parasite, a common cause of intraocular inflammation in the world. The treatment of toxoplasmosis is the sulfonamide group of drugs, which acts on tachyzoites forms, no acting on bradyzoites, that grown from latent focus located on boards and are responsible for recurrence. The investigators study aims to determine the effect of prophylactic therapy with Trimethoprim-sulfamethoxazole on the recurrences of toxoplasma retinochoroiditis gondii. This is a randomized, double-masked, in patients with eye condition of acute Toxoplasma gondii retinochoroiditis. The study population consist of patients treated at Ophthalmology department, University of Campinas. They present symptoms compatible with a diagnosis of Recurrent ocular toxoplasmosis. Volunteers will be recruited with a previous diagnosis of chorioretinitis presumed Toxoplasma gondii, which show active lesions compatible with recurrence. After the acute phase of treatment of all patients [1 tablet Trimethoprim-sulfamethoxazole (800/160mg) 12/12h during 45 days], the same Stratified by gender) will be randomized in a 1: 1 ratio between the group 1 (prophylactic treatment with trimethoprim-sulfamethoxazole tablet every other day) or group 2 (consisting of a placebo pill containing no active ingredient of similar appearance to trimethoprim-sulfamethoxazole, 1 time a day to day alternate). The definition of a patient with a recurrent episode of chorioretinitis Toxoplasmosis is the presence of old scars of chorioretinitis, associated with satellite active lesions chorioretinitis with positive IgG and IgM negative for toxoplasmosis. The patients will be tested for visual acuity, examination biomicroscopy, tonometry, fundus photography and indirect ophthalmoscopy. In each study, patients will be randomized in blocks of four (two in group I and two Group II) with stratification by gender. The primary outcome is incidence of episodes of recurrent chorioretinitis by toxoplasmosis in the follow up of 12 months. It was planned a minimum sample of 140 patients (70 in group I and 70 in group II). Assuming an incidence of 6% recurrence in group A, this sample will have a 80% power to detect a difference of 18% between groups. The results of this analysis will be considered significant if p <0. 05.

Official title: Influence of Trimethoprim-sulfamethoxazole for the Recurrence of Retinochoroiditis Toxoplasma Gondii

Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Prevention

Primary outcome: Incidence of episodes of recurrent chorioretinitis by toxoplasmosis in the follow up of 12 months.

Detailed description: The main variables are age, sex, presence of unilateral or bilateral eye injury, number of recurrences, number and location of lesions, and previous treatment for ocular toxoplasmosis. Patients will be followed during the two years in uveitis clinic at intervals defined as follows: return weekly for 4 weeks, monthly for 3 months and finally, 3/3 months. Patients will be trained to return immediately if they have any of the following symptoms: decreased visual acuity, photophobia, floaters or ocular hyperemia. Adverse events will be monitored. The definition of a patient with a recurrent episode of chorioretinitis Toxoplasmosis is the presence of old scars of chorioretinitis, associated with active satellite lesions chorioretinitis with positive IgG and IgM negative for toxoplasmosis. To data collection, will be used semi-structured questionnaire, containing the patient record, age, gender, visual acuity by ETDRS chart, the affected eye and previous treatment for ocular toxoplasmosis.

Minimum age: 18 Years. Maximum age: 60 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Positive test results for toxoplasmosis(IgM or IgG)

- Scars of retina compatible with toxoplasmosis

- Active lesion of chorioretinitis

Exclusion Criteria:

- Under 18 years of age

- Immunosuppressed patients

- Use of immunosuppressive treatments

- Concomitant chorioretinitis of other causes

João Paulo F. Felix, Phone: 19 3521 7396, Email: joaopaulofelix@hotmail.com

University of Campinas - Ophthalmology Department, Campinas, São Paulo 13083570, Brazil; Recruiting
João Paulo F. Felix, Phone: 19 3521 7396, Email: joaopaulofelix@hotmail.com
Rodrigo Pessoa C. Lira, Email: rodrigopclira@hotmail.com
João Paulo F Felix, Resident, Principal Investigator
Rodrigo P C Lira, PhD, Principal Investigator

University of Campinas

Related publications:

Opremcak EM, Scales DK, Sharpe MR. Trimethoprim-sulfamethoxazole therapy for ocular toxoplasmosis. Ophthalmology. 1992 Jun;99(6):920-5.

Soheilian M, Sadoughi MM, Ghajarnia M, Dehghan MH, Yazdani S, Behboudi H, Anisian A, Peyman GA. Prospective randomized trial of trimethoprim/sulfamethoxazole versus pyrimethamine and sulfadiazine in the treatment of ocular toxoplasmosis. Ophthalmology. 2005 Nov;112(11):1876-82. Epub 2005 Sep 19.

Gilbert RE, See SE, Jones LV, Stanford MS. Antibiotics versus control for toxoplasma retinochoroiditis. Cochrane Database Syst Rev. 2002;(1):CD002218. Review.

Starting date: October 2011
Last updated: December 2, 2014