Tolerability of IM penicillin G benzathine diluted or not with local anesthetics, or different gauge needles for syphilis treatment: a randomized clinical trial

• Published in: BMC infectious diseases 2019-10, Vol.19 (1), p.883-883, Article 883
• Main Authors: Estrada, Vicente, Santiago, Eva, Cabezas, Inmaculada, Cotano, Juan Luis, Carrió, Juan Carlos, Fuentes-Ferrer, Manuel, Vera, Mar, Ayerdi, Oskar, Rodríguez, Carmen, López, Laura, Cabello, Noemí, Núñez, María José, Puerta, Teresa, Sagastagoitia, Iñigo, Del Romero, Jorge
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; AIDS-Related Opportunistic Infections - drug therapy; Analysis; Anesthesia; Anesthetics; Anesthetics, Local - administration & dosage; Anesthetics, Local - adverse effects; Anesthetics, Local - therapeutic use; Care and treatment; Clinical trials; Diagnosis; Double-Blind Method; Drug Combinations; Female; HIV; HIV infections; HIV Infections - microbiology; Humans; Infection; Injections, Intramuscular - instrumentation; Intramuscular injections; Male; Mepivacaine; Mepivacaine - administration & dosage; Mepivacaine - adverse effects; Mepivacaine - therapeutic use; Needles; Pain - drug therapy; Penicillin G; Penicillin G Benzathine; Penicillin G Benzathine - administration & dosage; Penicillin G Benzathine - adverse effects; Penicillin G Benzathine - therapeutic use; Penicillins; Practice guidelines (Medicine); Questionnaires; Sexually transmitted diseases; Syphilis; Syphilis - drug therapy; Syphillis
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/s12879-019-4490-5

Penicillin G Benzathine (PGB) is the cornerstone of syphilis treatment. However, its intramuscular (IM) administration is associated with pain at the site of injection. The dilution of PGB with local anesthetics is recommended in some guidelines, but the evidence that supports it, particularly in adults and in HIV infection, is scarce. Preliminary clinical experience also suggests that the IM administration of PGB through increased needle gauges might improve its tolerability. The aim of the study to identify less painful ways of administering IM PGB in the treatment of syphilis in adults. Multicenter, randomized, double-blinded clinical trial in patients diagnosed with primary syphilis that required a single IM injection of PGB 2400,00 IU. Patients were randomized to receive PGB diluted with 0.5 mL mepivacaine 1% (MV) or PGB alone, and both groups either with a long 19G or short 21G IM needle. The primary objective was the effect on local pain immediately after the administration through a visual scale questionnaire on pain (0 to 10). One hundred eight patients were included, 27 in each group. Ninety-four (94.4%) were male, and 41.7% were also HIV-infected. Mean age 36.6 years (SD 11). Significant differences in immediate pain intensity were observed when comparing the long 19G group with anesthesia (mean pain intensity, [MPI] 2.92 [CI 95% 1.08-4.07]) vs long 19G without anesthesia (MPI 5.56 [CI 95% 4.39-6.73), p