On July 10, 2025 Pfizer issued a voluntary recall of certain lots of long-acting intramuscular (IM) benzathine penicillin G (Bicillin L-A) due to particulates identified during visual inspection. The CDC has issued a "Dear Colleague Letter" to alert healthcare providers about the recall and provide advice on how to manage the potentially limited supply of the drug for treatment of syphilis, which has been increasing in the US.2 Benzathine penicillin G is also used for treatment of group A streptococcal pharyngitis and prophylaxis of rheumatic fever.

The FDA has approved vonoprazan, a potassium-competitive acid blocker, copackaged with amoxicillin (Voquezna Dual Pak – Phathom) and with amoxicillin and clarithromycin (Voquezna Triple Pak) for treatment of Helicobacter pylori infection in adults. Vonoprazan is the first potassium-competitive acid blocker to be approved in the US. It has been available in Japan for treatment of various acid-related disorders since 2014. Vonoprazan is not available alone in the US.

Artesunate for injection (Amivas LLC), a semi-synthetic artemisinin derivative, is now approved by the FDA for initial (induction) treatment of severe malaria in children and adults. It has been available from the CDC on a compassionate use basis since 2007. Artemether/lumefantrine (Coartem), another artemisinin-based drug, was approved earlier for oral treatment of uncomplicated Plasmodium falciparum malaria. IV artesunate is now the only FDA-approved injectable antimalarial drug available in the US; IV quinidine has been discontinued.

The FDA has approved a fixed-dose combination of omeprazole, amoxicillin, and rifabutin (Talicia – RedHill) for treatment of Helicobacter pylori infection in adults. Talicia is the first rifabutin-based product to be approved for this indication.

H2-RECEPTOR ANTAGONISTS (H2RAs) — Currently available H2RAs are listed in Table 1. These drugs inhibit the action of histamine at the H2-receptor of the gastric parietal cell, decreasing basal acid secretion and, to a lesser degree, food-stimulated acid secretion. All H2RAs are about equally effective for treatment of PUD and GERD. H2RAs are faster acting than PPIs in relieving symptoms of dyspepsia or GERD, but they are not as effective as PPIs in relieving symptoms or in healing erosive esophagitis. Repeated administration of H2RAs leads to pharmacologic tolerance and has been associated with the development of new dyspeptic symptoms. Rebound acid hypersecretion can occur after stopping H2RAs.

The text that follows reviews some common bacterial infections and their empiric treatment pending the results of culture and susceptibility testing. The recommendations made here are based on the results of susceptibility studies, clinical trials, and the opinions of Medical Letter reviewers. Tables 1 and 2 list the usual dosages of antibacterial drugs.

Peptic ulcer disease (PUD) is usually caused by nonsteroidal anti-inflammatory drugs (NSAIDs) or by infection with Helicobacter pylori. Gastroesophageal reflux disease (GERD) can be caused by transient lower esophageal sphincter relaxation, reduced lower esophageal sphincter tone, hiatal hernia, delayed gastric emptying or hormonal changes due to pregnancy. Acid suppressive therapy is the cornerstone of management for both PUD and GERD.

Healthcare providers are often asked if patients can use drugs after their expiration date. Pharmaceutical companies, because of legal restrictions and liability concerns, will not sanction such use and might not even comment on the safety or effectiveness of using their products beyond the date on the label. Since the last Medical Letter publication on this subject, more data have become available.

The pathogenesis of acne is multifactorial: follicular hyperkeratinization, bacteria, sebum production, androgens and inflammation all play a role. The gram-positive microaerophilic bacteria Propionibacterium acnes promote development of acne lesions by secreting chemotactic factors that attract leukocytes to the follicle, causing inflammation.

Peptic ulcers caused by treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) are mainly gastric ulcers. Most duodenal and other gastric ulcers are caused by the gram-negative bacillus Helicobacter pylori. Gastroesophageal reflux disease (GERD) is caused by gastric acid reflux into the esophagus. Drugs that suppress gastric acid production are the primary treatment for GERD and peptic ulcers.

Information about empirical treatment of bacterial infections, emerging trends in antimicrobial resistance, new drugs and new data about older drugs continue to become available. Usual pathogens and empiric treatment for some common types of infections are summarized in the text and a table listing the drugs of choice and alternatives for each pathogen begins on page 40. The recommendations made here are based on the results of susceptibility studies, clinical trials and the opinions of Medical Letter consultants.

A new once-daily, low-dose oral formulation of doxycycline monohydrate (Oracea - CollaGenex) has been approved by the FDA for treatment of inflammatory papules and pustules associated with rosacea in adults.

The FDA has approved an extended-release formulation of minocycline (Solodyn - Medicis) for once-daily treatment of non-nodular moderate to severe acne.

Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table below lists first-choice and alternative drugs for most parasitic infections. The brand names and manufacturers of the drugs are listed in this article.

New drugs for bacterial infections and new information about older drugs continue to become available. Empirical treatment of some common bacterial infections is discussed in this article. A table listing the drugs of choice and alternatives for each pathogen begins on page 18. These recommendations are based on results of susceptibility studies, clinical trials and the opinions of Medical Letter consultants. Local resistance patterns should be taken into account. Trade names are listed on page 24.

Most peptic ulcers not caused by nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with infection of the gastric mucosa by the gram-negative bacilli Helicobacter pylori. The majority of NSAID-related ulcers are gastric. H. pylori infection causes both duodenal and gastric ulcers. Eradication of H. pylori promotes healing and markedly decreases recurrence of both duodenal and gastric ulcers (A Shiotamni and DY Graham, Med Clin North Am 2002; 86:1447; FKL Chan and WK Leung, Lancet 2002; 360:933). The first step in the management of peptic ulcers is the diagnosis and treatment of H. pylori.

Physicians and pharmacists are often asked if patients can use drugs after their expiration date. Pharmaceutical companies, because of legal restrictions and liability concerns, will not sanction such use and may not even comment on the safety or effectiveness of using their products beyond the date on the label.

Superseded--purchase updated Parasitic Infections article
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites.

Note: Drugs for Parasitic Infections, revised and updated, is now available to both subscribers and nonsubscribers on our web site. This article, a bi-annual feature of The Medical Letter for many years, will not be published as a printed issue in 2002, but is included in the 16th edition of The Medical Letter Handbook of Antimicrobial Therapy. The handbook is now available and can be ordered by calling customer service at 1-800-211-2769.

A fixed-dose combination of atovaquone and proguanil hydrochloride has been approved by the FDA for oral prophylaxis and treatment of malaria due to Plasmodium falciparum, including choloroquine-resistant strains.

Concerns persist about the possible use of biological weapons. Among the many organisms found in nature that cause serious infections, only a few have the combination of pathogenicity, stability and ease of production needed to make effective biological warefare agents.

(Superseded by the 2013 version. Click here to purchase.)
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table lists first-choice and alternative drugs for most parasitic infections.

The US Food and Drug Administration (FDA) has approved two new retinoids for treatment of psoriasis. Tazarotene gel 0.05% and 0.1% (Tazorac - Allergan) is being marketed for topical use in patients with stable, mild to moderate plaque psoriasis. Acitretin (Soriatane - Roche) is being promoted for systemic use in severe psoriasis.

Most peptic ulcers not caused by nonsteroidal anti-inflammatory drugs (NSAIDs) are now thought to be associated with infection of the gastric mucosa by the gram-negative bacilli Helicobacter pylori. The majority of NSAID-related ulcers are gastric. H. pylori have been associated with both duodenal and gastric ulcers. Eradication of H. pylori promotes healing and markedly decreases recurrence of both duodenal and gastric ulcers (AH Soll, JAMA, 275:622, 1996).

Physicians and pharmacists are often asked if patients can use drugs after their expiration date. Pharmaceutical companies, because of legal restrictions and liability concerns, will not sanction such use and may not even comment on the safety or effectiveness of using their products beyond the date on the label.

The US Food and Drug Administration (FDA) recently approved the marketing of clarithromycin (Biaxin - Abbott), a macrolide antibiotic, and omeprazole (Prilosec - Astra Merck), a proton pump inhibitor, for concurrent use in treatment of duodenal ulcers associated with Helicobacter pylori.

Most peptic ulcers not caused by nonsteroidal anti-inflammatory drugs (NSAIDs) are now thought to be associated with infection of the gastric mucosa by the gram-negative bacilli Helicobacter pylori (NIH Consensus Development Panel, JAMA, 272:65, July 6, 1994). NSAID-related ulcers are usually gastric. H. pylori have been associated with both duodenal and gastric ulcers.

Drugs that accelerate healing and prevent relapse or reurrence of peptic ulcers act either by decreasing gastric acidity or by enhancing mucosal defense mechanisms. Risk factors that may cause breakdown of mucosal defenses include the use of aspirinor other nonsteroidal anti-inflammatory drugs (NSAIDs) and the presence of Helicobacter pylori bacterial in the gastric antrum (AH Soll, Engl J Med, 322:909, 1990; WL Peterson, N Engl J Med, 324:1043, 1991).

An ophthalmic formulation of ciprofloxacin hydrochloride (Ciloxan - Alcon), a fluoroquinolone antibiotic, was recently marketed in the USA for treatment of bacterial keratitis and conjunctivitis. Ciprofloxacin has been used orally (Cipro) to treat a variety of serious infections (Medical Letter, 30:11, 1988) and recently was approved for intravenous administration.