Cefaclor Side Effects

Medically reviewed by Drugs.com. Last updated on Sep 28, 2023.

Applies to cefaclor: oral capsules, oral extended-release tablets, oral for suspension.

Side effects include:

Diarrhea, genital pruritus or vaginitis, headache, nausea, vomiting, rash.

For healthcare professionals

Applies to cefaclor: oral capsule, oral powder for reconstitution, oral tablet chewable, oral tablet extended release.

General

ER TABLETS: The most commonly reported side effects included headache, rhinitis, diarrhea, and nausea.

IR CAPSULES: The most commonly reported side effects included abdominal pain, diarrhea, morbilliform eruptions, and hypersensitivity reactions.

CR/MR TABLETS: The most commonly reported side effects included headache, diarrhea, nausea, and vaginal moniliasis.

ORAL SUSPENSION: The most commonly reported side effects included diarrhea and hypersensitivity reactions.^[Ref]

Gastrointestinal

ER TABLETS:

• Common (1% to 10%): Abdominal pain, diarrhea, nausea
• Uncommon (0.1% to 1%): Constipation, dyspepsia, flatulence, gastritis, nausea and vomiting, vomiting
• Postmarketing reports: Pseudomembranous colitis symptoms

IR CAPSULES:

• Common (1% to 10%): Diarrhea
• Rare (0.01% to 0.1%): Nausea, vomiting
• Frequency not reported: Abdominal pain, colitis, pseudomembranous colitis

CR/MR TABLETS:

• Common (1% to 10%): Abdominal pain, diarrhea, nausea
• Frequency not reported: Colitis, dyspepsia, pseudomembranous colitis, vomiting

ORAL SUSPENSION:

• Common (1% to 10%): Diarrhea, gastrointestinal symptoms
• Rare (0.01% to 0.1%): Colitis, pseudomembranous colitis, nausea, vomiting
• Frequency not reported: Abdominal pain^[Ref]

Dermatologic

ER TABLETS:

• Common (1% to 10%): Pruritus
• Uncommon (0.1% to 1%): Maculopapular rash, rash, sweating, urticaria
• Frequency not reported: Erythema multiforme
• Postmarketing reports: Face edema, Stevens-Johnson syndrome, toxic epidermal necrolysis

IR CAPSULES:

• Common (1% to 10%): Morbilliform eruption
• Very rare (less than 0.01%): Pruritus, urticaria
• Frequency not reported: Erythema multiforme, face edema, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis

CR/MR TABLETS:

• Common (1% to 10%): Pruritus, rash, urticaria
• Frequency not reported: Erythema multiforme, erythema multiforme minor, face edema, morbilliform eruptions, Stevens-Johnson syndrome, toxic epidermal necrolysis

ORAL SUSPENSION:

• Common (1% to 10%): Morbilliform eruptions
• Uncommon (0.1% to 1%): Erythema multiforme, pruritus, rash, urticaria
• Rare (0.01% to 0.1%): Erythema multiforme major, Stevens-Johnson syndrome, toxic epidermal necrolysis
• Frequency not reported: Erythema multiforme minor, face edema^[Ref]

Genitourinary

ER TABLETS:

• Common (1% to 10%): Vaginal moniliasis, vaginitis
• Uncommon (0.1% to 1%): Dysmenorrhea, dysuria, leukorrhea, menstrual disorder, nocturia
• Postmarketing reports: Abnormal urinalysis, genital pruritus

IR CAPSULES:

• Frequency not reported: Abnormal urinalysis, false positive test for urinary glucose, genital pruritus, vaginal moniliasis, vaginitis

CR/MR TABLETS:

• Common (1% to 10%): Vaginal moniliasis, vaginitis
• Frequency not reported: Abnormal urinalysis, genital pruritus, hematuria, proteinuria, pyuria

ORAL SUSPENSION:

• Frequency not reported: Abnormal urinalysis, false positive test for urinary glucose, genital pruritus, hematuria, proteinuria, pyuria, vaginal moniliasis, vaginitis^[Ref]

Respiratory

ER TABLETS:

• Common (1% to 10%): Cough increased, pharyngitis, rhinitis
• Uncommon (0.1% to 1%): Asthma, bronchitis, lung disorder, respiratory disorder, sinusitis

IR CAPSULES:

• Frequency not reported: Dyspnea

CR/MR TABLETS:

• Common (1% to 10%): Epistaxis
• Frequency not reported: Dyspnea

ORAL SUSPENSION:

• Frequency not reported: Dyspnea^[Ref]

Hypersensitivity

ER TABLETS:

• Uncommon (0.1% to 1%): Serum sickness-like reaction
• Frequency not reported: Hypersensitivity reactions, severe hypersensitivity reactions
• Postmarketing reports: Allergic reaction, anaphylactoid events, anaphylaxis, angioedema

IR CAPSULES:

• Common (1% to 10%): Hypersensitivity reactions
• Uncommon (0.1% to 1%): Serum sickness-like reaction
• Frequency not reported: Anaphylactoid events, anaphylaxis, angioedema, severe hypersensitivity reactions

CR/MR TABLETS:

• Rare (0.01% to 0.1%): Serum sickness-like reaction
• Frequency not reported: Allergic reactions, anaphylactoid events, anaphylaxis, angioedema, severe hypersensitivity reactions

ORAL SUSPENSION:

• Common (1% to 10%): Hypersensitivity reactions
• Uncommon (0.1% to 1%): Serum sickness-like reactions
• Rare (0.01% to 0.1%): Anaphylaxis, angioedema
• Frequency not reported: Anaphylactoid events^[Ref]

Anaphylaxis may occur more frequently in patients with a history of penicillin allergy.

Hypersensitivity reaction symptoms may persist for several months.

Serum-sickness-like reactions were more frequently reported in pediatric patients and after a second/subsequent course of treatment; reactions have been characterized by arthritis/arthralgia, erythema multiforme, and rash with or without fever.^[Ref]

Musculoskeletal

ER TABLETS:

• Common (1% to 10%): Back pain
• Uncommon (0.1% to 1%): Arthralgia, creatine phosphokinase increased, myalgia, neck pain, somnolence
• Frequency not reported: Arthritis

IR CAPSULES:

• Frequency not reported: Arthralgia, arthritis

CR/MR TABLETS:

• Frequency not reported: Arthralgia, arthritis

ORAL SUSPENSION:

• Frequency not reported: Arthralgia, arthritis^[Ref]

Nervous system

ER TABLETS:

• Common (1% to 10%): Headache
• Uncommon (0.1% to 1%): Dizziness, somnolence, tremor
• Postmarketing reports: Hypertonia, paresthesia, reversible hyperactivity, syncope, vertigo

IR CAPSULES:

• Rare (0.01% to 0.1%): Dizziness, hypertonia, reversible hyperactivity, somnolence
• Frequency not reported: Paresthesia, seizures, syncope

CR/MR TABLETS:

• Common (1% to 10%): Headache
• Frequency not reported: Dizziness, hypertonia, paresthesia, reversible hyperactivity, seizures, somnolence, syncope

ORAL SUSPENSION:

• Rare (0.01% to 0.1%): Dizziness, hypertonia, reversible hyperactivity, somnolence
• Frequency not reported: Paresthesia, seizures, syncope^[Ref]

Hematologic

ER TABLETS:

• Uncommon (0.1% to 1%): Eosinophils increased, erythrocyte count decreased, hemoglobin decreased, lymphocytes decreased, mean cell volume (MCV) increased, neutrophils segmented decreased, platelet count decreased
• Postmarketing reports: Eosinophilia, hemolytic anemia, leukopenia, neutropenia, positive direct Coombs test, transient thrombocytopenia

IR CAPSULES:

• Rare (0.01% to 0.1%): Agranulocytosis, aplastic anemia, hemolytic anemia, reversible neutropenia (may be of clinical significance), thrombocytopenia
• Very rare (less than 0.01%): Positive Coombs test
• Frequency not reported: Eosinophilia, pancytopenia, transient leukopenia, transient lymphocytosis
• Postmarketing reports: Increased prothrombin time with/without clinical bleeding

CR/MR TABLETS:

• Frequency not reported: Agranulocytosis, aplastic anemia, eosinophilia, hemolytic anemia, increased prothrombin time with/without clinical bleeding, leukopenia, lymphadenopathy, lymphocytosis, neutropenia (may be of clinical significance), positive direct Coombs test, transient fluctuations in leukocyte count, transient thrombocytopenia

ORAL SUSPENSION:

• Uncommon (0.1% to 1%): Positive Coombs test
• Rare (0.01% to 0.1%): Agranulocytosis, aplastic anemia, hemolytic anemia, reversible neutropenia (may be of clinical significance), thrombocytosis, thrombocytopenia
• Frequency not reported: Eosinophilia, leukopenia, lymphadenopathy, pancytopenia, transient fluctuations in leukocyte count, transient lymphocytosis
• Postmarketing reports: Increased prothrombin time with/without clinical bleeding^[Ref]

Increased prothrombin time with/without clinical bleeding was reported in patients given IR capsules and warfarin concurrently.

Transient fluctuations in leukocyte count most commonly occurred in infants and young children.^[Ref]

Other

ER TABLETS:

• Uncommon (0.1% to 1%): Accidental injury, chills, ear pain, fever, malaise, otitis media, pain, surgical procedure

IR CAPSULES:

• Frequency not reported: Asthenia, fever

CR/MR TABLETS:

• Common (1% to 10%): Asthenia, pain
• Frequency not reported: Fever

ORAL SUSPENSION:

• Rare (0.01% to 0.1%): Fever
• Frequency not reported: Asthenia^[Ref]

Metabolic

ER TABLETS:

• Uncommon (0.1% to 1%): Albumin decreased, anorexia, calcium increased, phosphorus increased, potassium increased, sodium decreased/increased^[Ref]

Cardiovascular

EXTENDED RELEASE (ER) TABLETS:

• Uncommon (0.1% to 1%): Chest pain, congestive heart failure, edema, palpitation, peripheral edema
• Postmarketing reports: Hypotension, limb edema, vasodilation

IMMEDIATE RELEASE (IR) CAPSULES:

• Frequency not reported: Hemorrhage, hypotension, limb edema, vasodilation

MODIFIED RELEASE (CR/MR) TABLETS:

• Frequency not reported: Limb edema, vasodilation

ORAL SUSPENSION:

• Frequency not reported: Hemorrhage, hypotension, limb edema, vasodilation^[Ref]

Hepatic

ER TABLETS:

• Uncommon (0.1% to 1%): Alkaline phosphatase increased, ALT increased, GGT increased, total bilirubin increased
• Postmarketing reports: Cholestasis, liver dysfunction, transient AST elevation

IR CAPSULES:

• Rare (0.01% to 0.1%): Cholestatic jaundice, transient hepatitis
• Frequency not reported: Elevated bilirubin, elevated LDH, slight alkaline phosphatase elevations, slight ALT elevations, slight AST elevations

CR/MR TABLETS:

• Frequency not reported: Cholestasis, cholestatic jaundice, liver dysfunction, transient alkaline phosphatase elevations, transient ALT elevations, transient AST elevations, transient hepatitis

ORAL SUSPENSION:

• Rare (0.01% to 0.1%): Cholestatic jaundice, liver dysfunction, transient hepatitis
• Frequency not reported: Elevated bilirubin, elevated LDH, slight alkaline phosphatase elevations, slight ALT elevations, slight AST elevations^[Ref]

Psychiatric

ER TABLETS:

• Uncommon (0.1% to 1%): Anxiety, insomnia, nervousness
• Postmarketing reports: Confusion

IR CAPSULES:

• Rare (0.01% to 0.1%): Agitation, confusion, hallucinations, insomnia, nervousness

CR/MR TABLETS:

• Frequency not reported: Agitation, confusion, hallucinations, insomnia, nervousness

ORAL SUSPENSION:

• Rare (0.01% to 0.1%): Agitation, confusion, hallucinations, insomnia, nervousness^[Ref]

Renal

ER TABLETS:

• Uncommon (0.1% to 1%): Blood urea nitrogen (BUN) increased, creatinine increased
• Postmarketing reports: Reversible interstitial nephritis

IR CAPSULES:

• Rare (0.01% to 0.1%): Reversible interstitial nephritis
• Frequency not reported: Renal dysfunction, slight BUN elevations, slight serum creatinine elevations, toxic nephropathy

CR/MR TABLETS:

• Frequency not reported: Renal dysfunction, reversible interstitial nephritis, toxic nephropathy, transient serum creatinine increase, transient serum urea/BUN increase

ORAL SUSPENSION:

• Rare (0.01% to 0.1%): Reversible interstitial nephritis
• Frequency not reported: Renal dysfunction, slight elevation in serum creatinine, slight elevation in serum urea/BUN, toxic nephropathy^[Ref]

Ocular

ER TABLETS:

• Uncommon (0.1% to 1%): Conjunctivitis^[Ref]

Immunologic

ER TABLETS:

• Uncommon (0.1% to 1%): Flu syndrome, infection

IR CAPSULES:

• Frequency not reported: Moniliasis, superinfection

CR/MR TABLETS:

• Frequency not reported: Moniliasis

ORAL SUSPENSION:

• Frequency not reported: Moniliasis, superinfection^[Ref]

Further information

Cefaclor side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer