Gallbladder Disorders Overview

Formation of hardened deposits (gallstones) inside the gallbladder, usually made of cholesterol or bilirubin.

Obesity, rapid weight loss, pregnancy, Crohn's disease, and certain medications (e.g., octreotide, ceftriaxone).

Ultrasound (US) is the gold standard. It accurately detects gallstones in the gallbladder.

Persistent pain in the upper right abdomen (RUQ), fever, vomiting, and a positive Murphy's sign.

Gallbladder wall thickening (>5 mm) on ultrasound, pericholecystic fluid, and a positive Murphy's sign.

Presence of gallstones in the common bile duct (CBD).

RUQ colicky pain, fever, and jaundice (Charcot's triad).

Elevated levels of liver enzymes (AST, ALT, ALP), and bilirubin in the blood.

Antibiotics are crucial for managing choledocholithiasis and cholecystitis to control secondary infections and prevent complications. These conditions often involve biliary obstruction, making the biliary tract susceptible to bacterial colonization and infection.

Escherichia coli is the most frequent pathogen in biliary infections, followed by Klebsiella species. Proteus and Enterobacter species are less common but still significant.

Bacteroides fragilis is a common anaerobic bacteria found in polymicrobial biliary infections.

Enterococcus species are gram-positive cocci commonly found in biliary infections.

Ceftriaxone is a third-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins. It exhibits excellent coverage against gram-negative rods and some gram-positive organisms.

Metronidazole disrupts DNA synthesis in anaerobic bacteria by generating toxic free radicals. It provides excellent coverage against anaerobes, including Bacteroides fragilis.

Ceftriaxone + Metronidazole is a commonly used combination for managing biliary infections. Ceftriaxone targets the most common aerobic pathogens, while metronidazole provides coverage against anaerobes, addressing the polymicrobial nature of these infections.

Ceftriaxone: GI upset, biliary sludging (especially in neonates), risk of nephrotoxicity. Metronidazole: Metallic taste, peripheral neuropathy, disulfiram-like reaction with alcohol.

A combination of ceftriaxone and metronidazole, providing coverage against both aerobic and anaerobic bacteria commonly involved in biliary infections.

Used for moderate to severe biliary infections, including inflammation of the gallbladder (cholecystitis) and gallstones in the bile duct (choledocholithiasis).

Ampicillin inhibits bacterial cell wall synthesis, while sulbactam inhibits beta-lactamase enzymes, allowing ampicillin to work against bacteria that would normally break it down.

Effective against a wide range of bacteria, including gram-negative rods, anaerobes, and even some enterococcus species.

Piperacillin inhibits bacterial cell wall synthesis, similar to ampicillin, while tazobactam acts as a beta-lactamase inhibitor, extending its effectiveness against resistant organisms.

Effective against a broad spectrum of bacteria, making it a first-line choice for serious biliary infections, especially in cases of sepsis, due to its strong antibacterial action.

Fluoroquinolones inhibit DNA gyrase and topoisomerase IV, key enzymes involved in bacterial DNA replication, effectively stopping bacterial growth.

Often used in severe polymicrobial infections, or when sepsis or organ dysfunction is present, especially in cases of difficult infections.

Obstruction in the bile duct creates a high-pressure environment, slowing down bile flow and enabling bacteria to multiply.

Gram-negative bacteria like E. coli and Klebsiella travel from the intestines to the bile duct.

Anaerobic bacteria become significant in these infections, especially when multiple bacteria are involved.

Antibiotic treatment should target common culprits in biliary infections: gram-negative aerobes, gram-positive cocci, and anaerobes.

Mild to moderate cases can be treated with ceftriaxone and metronidazole or a single drug like ampicillin-sulbactam.

Severe cases and sepsis require stronger antibiotics like piperacillin-tazobactam or carbapenems to provide extended-spectrum coverage.

Antibiotics typically continue for 4-7 days after source control (e.g., ERCP or cholecystectomy).

Microperforation of diverticula allows bacteria to enter and cause an infection.

A common antibiotic effective against gram-negative bacteria like E. coli and Klebsiella.

Ceftriaxone is often chosen for patients allergic to penicillin.

Tendon pain or swelling can occur, particularly in older adults or those taking corticosteroids.

Ceftriaxone might prolong the QT interval on the ECG, increasing arrhythmia risk, especially with electrolyte issues.

Ceftriaxone can cause dizziness and confusion, particularly in older adults.

Metronidazole effectively targets anaerobic bacteria.

Metronidazole is essential for treating polymicrobial infections, as it provides anaerobic coverage alongside other antibiotics.

Metronidazole can damage nerves, particularly if used with alcohol.

Ampicillin-sulbactam is a good choice for patients who do not tolerate penicillin and need a single-agent therapy.

Gram-negative and anaerobic bacteria are commonly found in the digestive and urinary tracts, making them important players in infections of these areas. They often occur together, contributing to complex infections.

E. coli is the most common culprit in infections like peritonitis and UTIs that originate from the gut. Klebsiella species are often found in biliary infections and liver abscesses. Proteus species contribute to UTIs linked to the GI tract or procedures involving it.

Ceftriaxone targets a wide range of Gram-negative bacteria, including those often seen in biliary infections, making it a valuable choice for these infections.

Metronidazole effectively tackles anaerobic bacteria, which often coexist with Gram-negatives in biliary infections, making it a helpful addition to treatment.

The combination of Ceftriaxone and Metronidazole effectively addresses both aerobic and anaerobic bacteria commonly involved in biliary infections, providing broader coverage for these complex infections.

Ursodeoxycholic acid (UDCA) can be used to dissolve cholesterol gallstones, although it works slowly. It is often used as a first-line therapy in patients with cholesterol gallstones.

Tenofovir and entecavir are effective antiviral medications for hepatitis B, suppressing viral replication and improving liver function.

Direct-acting antivirals (DAAs) like Sofosbuvir and Velpatasvir are highly effective in clearing Hepatitis C infection, achieving high cure rates.