Population studies on drug hypersensitivities

A Vonoprazan, Clarithromycin, and Metronidazole Regimen as Helicobacter pylori Eradication Therapy for Patients with Penicillin Allergy in Light of Clarithromycin Resistance

Objective Vonoprazan (VPZ), clarithromycin (CAM), metronidazole (MNZ) and VPZ, MNZ, and sitafloxacin (STFX) regimen are all established Helicobacter pylori eradication therapies for patients with penicillin allergy in Japan. However, no study has assessed the efficacy of a VPZ, CAM, and MNZ (VCM) regimen in patients with clarithromycin resistance (CAM-R). We therefore assessed the efficacy of a VCM regimen for treating H. pylori infection in patients with CAM-R and penicillin allergy. Methods Fifty-three patients with penicillin allergy who received H. pylori eradication therapy were retrospectively analyzed. Eight patients received a 7-day proton-pump inhibitor, CAM, and MNZ (PCM) regimen; 35 patients [11 CAM-R, and 10 with clarithromycin sensitivity (CAM-S)] received 7-day VCM regimens; and 10 patients received 7-day VPZ, MNZ, and STFX (VMS) regimens. A 13C-urea breath test was used to determine eradication. The efficacy of eradication was evaluated via both intention-to-treat (ITT) and per-protocol (PP) analyses. Results According to ITT and PP analyses, eradication rates (ERs) with PCM, VCM, and VMS therapies were 50.0% and 50.0%, 94.3% and 100%, and 90% and 90%, respectively. Treatment was successful in all patients with CAM-S. For patients with CAM-R, treatment was successful in 10 patients, and 1 patient discontinued treatment owing to an adverse event. According to ITT and PP analyses, ERs were 90.9% and 100% in CAM-R, and were 100% and 100% in CAM-S, respectively. Conclusion The VCM regimen for H. pylori eradication may be a viable candidate therapy for patients with penicillin allergy, regardless of CAM-R.

Helicobacter pylori rescue treatment with vonoprazan, metronidazole, and sitafloxacin in the presence of penicillin allergy

Background and Aim

To assess the efficacy and safety of 7‐day Helicobacter pylori rescue treatment consisting of a vonoprazan (VPZ), metronidazole (MNZ), and sitafloxacin (STFX) regimen (VPZ‐MNZ‐STFX therapy) in patients with penicillin allergy.

Methods

This was a registered prospective intervention study. Patients with penicillin allergy who were diagnosed with H. pylori infection and had a history of H. pylori eradication were eligible for inclusion. Seventeen patients were prospectively treated with VPZ 20 mg bid, MNZ 250 mg bid, and STFX 100 mg bid for 7 days. Safety was evaluated using a questionnaire on adverse effects.

Results

The eradication rate of 7‐day VPZ‐MNZ‐SFTX therapy was 88.2% (95% confidence interval: 63.6–98.5%; n = 17) in both intention‐to‐treat and per‐protocol analyses. On the questionnaire, 25% of patients reported experiencing diarrhea, with a score of 2 or 3. All patients undergoing VPZ‐MNZ‐STFX therapy completed 100% of their medication course.

Conclusion

Rescue H. pylori eradication with VPZ‐MNZ‐STFX therapy is effective and well tolerated in patients with penicillin allergy (UMIN000016335, jRCTs031180133).

Role of Vonoprazan in Helicobacter pylori Eradication Therapy in Japan

Complete eradication of Helicobacter pylori is important for preventing the development of gastric cancer. The outcome of H. pylori eradication therapy is mainly dependent on bacterial susceptibility to antimicrobial agents and potent neutralization of intragastric pH across 24 h, especially when using acid-sensitive antimicrobial agents such as clarithromycin (CLR), amoxicillin and sitafloxacin. However, conventional regimens comprising twice-daily doses (bid) of proton pump inhibitors (PPIs) are generally insufficient for maintaining the required gastric acid secretion for 24 h for successful eradication in all H. pylori-positive patients. Further, the increasing prevalence of CLR-resistant strains with each year has led to a decrease in eradication rates of first-line PPI- and CLR-containing therapies in developed countries, including Japan. In 2015, the potassium-competitive acid blocker vonoprazan (VPZ) became clinically available in Japan. VPZ competitively inhibits H⁺/K⁺-ATPase activity more potently than PPIs (e.g., omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole). Therefore, a VPZ-containing H. pylori eradication regimen is expected to increase the eradication rate compared with conventional regimens containing a standard dose of PPI. In fact, a recent meta-analysis that investigated the efficacy of first-line eradication therapy showed that a VPZ-containing regimen achieved a higher eradication rate than a PPI-containing regimen. While the Maastricht V/Florence Consensus Report recommends selecting a bismuth or non-bismuth quadruple therapy and concomitant therapy for patients living in areas with high prevalence of CLR resistance, a VPZ-containing regimen demonstrates effectiveness for patients infected with CLR-resistant strains and patients living in areas where the prevalence of CLR-resistant strains is >15%. As a next step, studies are needed to determine the factors affecting the clinical outcome of VPZ-containing therapy and optimal VPZ-containing alternative regimens for tailored treatments. In this review, we summarize the advantages and disadvantages of VPZ in H. pylori eradication therapy.

First-Line Helicobacter pylori Eradication with Vonoprazan, Clarithromycin, and Metronidazole in Patients Allergic to Penicillin

Aim

To assess the efficacy of 7-day first-line Helicobacter pylori eradication with vonoprazan (VPZ), clarithromycin (CAM), and metronidazole (MNZ) in patients with penicillin allergy.

Methods

Patients with penicillin allergy, diagnosed with Helicobacter pylori infection and did not have history of Helicobacter pylori eradication, were eligible for the study. Twenty patients were prospectively treated with 20 mg VPZ twice daily, 200 or 400 mg CAM twice daily, and 250 mg MNZ twice daily for 7 days. We also collected the data from 30 patients retrospectively treated with proton pump inhibitor (PPI), CAM, and MNZ. Safety was evaluated in patients completing an adverse effect questionnaire.

Results

Both the intention-to-treat and per-protocol effectiveness of VPZ-based eradication were 100% (95% CI: 86.1–100%; n = 20). The eradication rates of PPI-based regimen were 83.3% (95% CI: 65.3–94.4%) in the ITT and 82.7% (95% CI: 64.2–94.2%) in the PP analyses. Abdominal fullness was more frequent in VCM compared to PCM. However, all patients with VCM regimen had taken 100% of their course of medication.

Conclusion

Triple therapy with VPZ, CAM, and MNZ is well tolerated and effective for eradicating Helicobacter pylori in patients allergic to penicillin. This study was registered in the UMIN Clinical Trials Registry as UMIN000016335.

Frequency of self-reported drug allergy: A systematic review and meta-analysis with meta-regression

BACKGROUND

Patients reporting drug allergy are treated with second-line therapies, with possible negative clinical and health consequences.

OBJECTIVE

To assess the prevalence of self-reported drug allergy.

METHODS

We performed a systematic review of observational studies assessing the prevalence of self-reported drug allergy. We searched 4 electronic databases. From selected studies, we extracted data on self-reported drug allergy prevalence, study design, participants' demographic characteristics, reported clinical manifestations, and suspected culprit drugs. We performed a random-effects meta-analysis followed by a meta-regression.

RESULTS

Fifty-three studies were included in the systematic review, assessing a total of 126,306 participants, of whom 8.3% (range across studies 0.7-38.5%) self-reported drug allergy. Cutaneous manifestations were reported by 68.2% of participants, and anaphylactic or systemic reactions were reported by 10.8%. Antibiotics, nonsteroidal anti-inflammatory drugs, and anesthetics were the most frequently reported culprit drug classes. The frequency of self-reported drug allergy was higher in female (11.4%) than in male (7.2%) patients, adults (10.0%) than in children (5.1%), and in studies in the medical setting (15.9% in inpatients, 11.4% in outpatients) than in the general population (5.9%). The meta-analysis rendered a pooled prevalence of 7.9% (95% confidence interval 6.4-9.6), and the meta-regression identified study region, participants' age group, and study setting as factors associated with significant heterogeneity. Confirmation tests (including skin, in vitro, and drug provocation tests) were performed in only 3 studies.

CONCLUSION

The prevalence of self-reported drug allergy is highly variable and is higher in female patients, adults, and inpatients. To overcome this variability, further studies using confirmation tests are needed.

Vonoprazan improves the efficacy of Helicobacter pylori eradication therapy with a regimen consisting of clarithromycin and metronidazole in patients allergic to penicillin

BACKGROUND

Although all Helicobacter pylori (H. pylori)-positive patients should receive eradication therapy, the therapy is a challenge for patients allergic to penicillin. There have been a few reports on the efficacy of eradication therapy for such patients.

OBJECTIVE

To analyze the efficacy of vonoprazan or proton pump inhibitor (PPI)-based 7-day triple therapy in patients allergic to penicillin.

MATERIALS AND METHODS

A total of 88 consecutive patients allergic to penicillin who received H. pylori eradication therapy were retrospectively analyzed. Thirty-one patients had a history of failed eradication therapy. Four 7-day regimens were prescribed during the study period: clarithromycin-metronidazole-PPI (13 patients), clarithromycin-metronidazole-vonoprazan (14 patients), metronidazole-sitafloxacin-PPI (44 patients) and metronidazole-sitafloxacin-vonoprazan (17 patients). A ¹³ C-urea breath test was used for confirmation of eradication, and efficacy of eradication was evaluated by "intention-to-treat" analysis and "per-protocol" analysis.

RESULTS

Intention-to-treat and per-protocol eradication rates were 46.2%/54.6% for patients who received clarithromycin-metronidazole-PPI, 92.9/92.9% for patients who received clarithromycin-metronidazole-vonoprazan, 100/100% for patients who received metronidazole-sitafloxacin-PPI and 88.2/93.8% for patients who received metronidazole-sitafloxacin-vonoprazan. For first eradication, vonoprazan significantly raised the intention-to-treat efficacy of the triple therapy including clarithromycin-metronidazole (vonoprazan: 92.9%, PPI: 46.2%, P=.0128). A 7-day regimen consisting of metronidazole and sitafloxacin was effective for patients allergic to penicillin with or without past failure of eradication.

CONCLUSION

For first eradication in patients allergic to penicillin, a 7-day triple therapy consisting of clarithromycin, metronidazole and vonoprazan could be a candidate eradication regimen.

Helicobacter pylori first-line and rescue treatments in the presence of penicillin allergy

BACKGROUND

Helicobacter pylori eradication is a challenge in penicillin allergy.

AIM

To assess the efficacy and safety of first-line and rescue treatments in patients allergic to penicillin.

METHODS

Prospective multicenter study. Patients allergic to penicillin were given a first-line treatment comprising (a) 7-day omeprazole-clarithromycin-metronidazole and (b) 10-day omeprazole-bismuth-tetracycline-metronidazole. Rescue treatments were as follows: (a) bismuth quadruple therapy; (b) 10-day PPI-clarithromycin-levofloxacin; and (c) 10-day PPI-clarithromycin-rifabutin. Eradication was confirmed by (13)C-urea breath test. Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated by questionnaires.

RESULTS

In total, 267 consecutive treatments were included. (1) First-line treatment: Per-protocol and intention-to-treat eradication rates with omeprazole-clarithromycin-metronidazole were 59 % (62/105; 95 % CI 49-62 %) and 57 % (64/112; 95 % CI 47-67 %). Respective figures for PPI-bismuth-tetracycline-metronidazole were 75 % (37/49; 95 % CI 62-89 %) and 74 % (37/50; 95 % CI (61-87 %) (p < 0.05). Compliance with treatment was 94 and 98 %, respectively. Adverse events were reported in 14 % with both regimens (all mild). (2) Second-line treatment: Intention-to-treat eradication rate with omeprazole-clarithromycin-levofloxacin was 64 % both after triple and quadruple failure; compliance was 88-100 %, with 23-29 % adverse effects (all mild). (3) Third-/fourth-line treatment: Intention-to-treat eradication rate with PPI-clarithromycin-rifabutin was 22 %.

CONCLUSION

In allergic to penicillin patients, a first-line treatment with a bismuth-containing quadruple therapy (PPI-bismuth-tetracycline-metronidazole) seems to be a better option than the triple PPI-clarithromycin-metronidazole regimen. A levofloxacin-based regimen (together with a PPI and clarithromycin) represents a second-line rescue option in the presence of penicillin allergy.

Eradication of H. pylori infection in patients allergic to penicillin using triple therapy with a PPI, metronidazole and sitafloxacin

Eradication of H. pylori in patients allergic to penicillin should be performed using regimens without penicillin derivatives. We treated a total of 28 patients allergic to penicillin with a proton pump inhibitor (PPI), metronidazole (250 mg bid) and sitafloxacin (100 mg bid) for one to two weeks. At four to eight weeks after the treatment, the patients underwent the [(13)C]-urea breath test. The overall eradication rate was 100.0%. Mild adverse events were observed. Triple therapy with a PPI, metronidazole and sitafloxacin is well tolerated and effective for the eradication of H. pylori in patients allergic to penicillin.