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Tamiflu (Oseltamivir Phosphate) - Side Effects and Adverse Reactions

 
 



ADVERSE REACTIONS

The following serious adverse reactions are discussed below and elsewhere in the labeling:

  • Serious skin and hypersensitivity reactions [see Warnings and Precautions]
  • Neuropsychiatric events [see Warnings and Precautions]

The most common adverse reactions are nausea and vomiting.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Treatment Studies in Adult Subjects

A total of 1171 subjects who participated in adult controlled clinical trials for the treatment of influenza were treated with TAMIFLU. The most frequently reported adverse events in these studies were nausea and vomiting. These events were generally of mild to moderate severity and usually occurred on the first 2 days of administration. Less than 1% of subjects discontinued prematurely from clinical trials due to nausea and vomiting.

Adverse events that occurred with an incidence of ≥1% in 1440 subjects taking placebo or TAMIFLU 75 mg twice daily in adult treatment studies are shown in Table 4. This summary includes 945 healthy young adults and 495 "at risk" subjects (elderly patients and patients with chronic cardiac or respiratory disease). Those events reported numerically more frequently in subjects taking TAMIFLU compared with placebo were nausea, vomiting, bronchitis, insomnia, and vertigo.

Prophylaxis Studies in Adult Subjects

A total of 4187 subjects (adolescents, healthy adults, and elderly) participated in prophylaxis studies, of whom 1790 received the recommended dose of 75 mg once daily for up to 6 weeks. Adverse events were qualitatively very similar to those seen in the treatment studies, despite a longer duration of dosing (see Table 4). Events reported more frequently in subjects receiving TAMIFLU compared to subjects receiving placebo in prophylaxis studies, and more commonly than in treatment studies, were aches and pains, rhinorrhea, dyspepsia and upper respiratory tract infections. However, the difference in incidence between TAMIFLU and placebo for these events was less than 1%. There were no clinically relevant differences in the safety profile of the 942 elderly subjects who received TAMIFLU or placebo, compared with the younger population.

Table 4 Most Frequent Adverse Events in Studies in Naturally Acquired Influenza in Subjects 13 Years of Age and Older
Treatment Prophylaxis
Adverse Event Placebo

N=716
TAMIFLU
75 mg twice daily
N=724
Placebo/
No Prophylaxis
N=1688
TAMIFLU
75 mg once daily
N=1790
Nausea (without vomiting) 40 (6%) 72 (10%) 56 (3%) 129 (7%)
Vomiting 21 (3%) 68 (9%) 16 (1%) 39 (2%)
Diarrhea 70 (10%) 48 (7%) 40 (2%) 50 (3%)
Bronchitis 15 (2%) 17 (2%) 22 (1%) 15 (1%)
Abdominal pain 16 (2%) 16 (2%) 25 (1%) 37 (2%)
Dizziness 25 (3%) 15 (2%) 21 (1%) 24 (1%)
Headache 14 (2%) 13 (2%) 306 (18%) 326 (18%)
Cough 12 (2%) 9 (1%) 119 (7%) 94 (5%)
Insomnia 6 (1%) 8 (1%) 15 (1%) 22 (1%)
Vertigo 4 (1%) 7 (1%) 4 (<1%) 4 (<1%)
Fatigue 7 (1%) 7 (1%) 163 (10%) 139 (8%)

Additional adverse events occurring in <1% of patients receiving TAMIFLU for treatment included unstable angina, anemia, pseudomembranous colitis, humerus fracture, pneumonia, pyrexia, and peritonsillar abscess.

Treatment Studies in Pediatric Subjects

A total of 1032 pediatric subjects aged 1 to 12 years (including 698 otherwise healthy pediatric subjects aged 1 to 12 years and 334 asthmatic pediatric subjects aged 6 to 12 years) participated in controlled clinical trials of TAMIFLU given for the treatment of influenza. A total of 515 pediatric subjects received treatment with TAMIFLU for oral suspension.

Adverse events occurring in ≥1% of pediatric subjects receiving TAMIFLU treatment are listed in Table 5. The most frequently reported adverse event was vomiting. Other events reported more frequently by pediatric subjects treated with TAMIFLU included abdominal pain, epistaxis, ear disorder, and conjunctivitis. These events generally occurred once and resolved despite continued dosing resulting in discontinuation of drug in 8 out of 515 (2%) cases.

The adverse event profile in adolescents is similar to that described for adult subjects and pediatric subjects aged 1 to 12 years.

Prophylaxis Studies in Pediatric Subjects

Pediatric subjects aged 1 to 12 years participated in a postexposure prophylaxis study in households, both as index cases (n=134) and as contacts (n=222). Gastrointestinal events were the most frequent, particularly vomiting. In a separate 6-week, uncontrolled, pediatric seasonal prophylaxis study (n=49), the adverse events noted were consistent with those previously observed (see Table 5).

Table 5 Most Frequent Adverse Events Occurring in Children Aged 1 to 12 Years in Studies in Naturally Acquired Influenza
Treatment Trials Household Prophylaxis Trial
Adverse Event Placebo

N=517
TAMIFLU
2 mg/kg twice daily
N=515
No Prophylaxis 1
N=87
Prophylaxis with TAMIFLU
once daily
N=99
Vomiting 48 (9%) 77 (15%) 2 (2%) 10 (10%)
Diarrhea 55 (11%) 49 (10%) - 1 (1%)
Otitis media 58 (11%) 45 (9%) 2 (2%) 2 (2%)
Abdominal pain 20 (4%) 24 (5%) - 3 (3%)
Asthma (including aggravated) 19 (4%) 18 (3%) 1 (1%) 1 (1%)
Nausea 22 (4%) 17 (3%) 1 (1%) 4 (4%)
Epistaxis 13 (3%) 16 (3%) - 1 (1%)
Pneumonia 17 (3%) 10 (2%) 2 (2%) -
Ear disorder 6 (1%) 9 (2%) - -
Sinusitis 13 (3%) 9 (2%) - -
Bronchitis 11 (2%) 8 (2%) 2 (2%) -
Conjunctivitis 2 (<1%) 5 (1%) - -
Dermatitis 10 (2%) 5 (1%) - -
Lymphadenopathy 8 (2%) 5 (1%) - -
Tympanic membrane disorder 6 (1%) 5 (1%) - -

1 Unit dose = age-based dosing of 30 mg, 45 mg, or 60 mg

Prophylaxis Study in Immunocompromised Subjects

In a 12-week seasonal prophylaxis study in 475 immunocompromised subjects, including 18 pediatric subjects 1 to 12 years of age, the safety profile in the 238 subjects receiving TAMIFLU was consistent with that previously observed in other TAMIFLU prophylaxis clinical trials.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of TAMIFLU. Because these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency or establish a causal relationship to TAMIFLU exposure.

Body as a Whole: Swelling of the face or tongue, allergy, anaphylactic/anaphylactoid reactions, hypothermia

Dermatologic: Rash, dermatitis, urticaria, eczema, toxic epidermal necrolysis, Stevens-Johnson Syndrome, erythema multiforme [see Warnings and Precautions]

Digestive: Hepatitis, liver function tests abnormal

Cardiac: Arrhythmia

Gastrointestinal disorders: Gastrointestinal bleeding, hemorrhagic colitis

Neurologic: Seizure

Metabolic: Aggravation of diabetes

Psychiatric: Abnormal behavior, delirium, including symptoms such as hallucinations, agitation, anxiety, altered level of consciousness, confusion, nightmares, delusions [see Warnings and Precautions]



REPORTS OF SUSPECTED TAMIFLU SIDE EFFECTS / ADVERSE REACTIONS

Below is a sample of reports where side effects / adverse reactions may be related to Tamiflu. The information is not vetted and should not be considered as verified clinical evidence.

Possible Tamiflu side effects / adverse reactions in 29 year old male

Reported by a physician from France on 2011-10-14

Patient: 29 year old male

Reactions: Hallucination

Suspect drug(s):
Tamiflu



Possible Tamiflu side effects / adverse reactions in 63 year old male

Reported by a physician from United States on 2011-10-15

Patient: 63 year old male weighing 90.9 kg (200.0 pounds)

Reactions: Hypotension

Suspect drug(s):
Tamiflu

Other drugs received by patient: Amoxicillin; Diovan HCT; Levothyroxine Sodium; Wellbutrin



Possible Tamiflu side effects / adverse reactions in 33 year old female

Reported by a physician from Japan on 2011-10-25

Patient: 33 year old female

Reactions: Stevens-Johnson Syndrome, Liver Disorder

Suspect drug(s):
Tamiflu



See index of all Tamiflu side effect reports >>

Drug label data at the top of this Page last updated: 2011-10-05

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