In the paragraphs that follow, the incidence of less commonly reported adverse events in four placebo-controlled trials are presented. Variability associated with adverse event reporting, the terminology used to describe adverse events etc, limit the value of the incidence estimates provided. The incidence of each adverse event is calculated as the number of patients reporting the event at least once divided by the number of patients who used FROVA. All adverse events reported within 48 hours of drug administration in the first attack in four placebo controlled trials involving 2392 patients (1554 frovatriptan 2.5 mg and 838 placebo) are included, except those already listed in Table 2, those too general to be informative, those not reasonably associated with the use of the drug and those which occurred at the same or a greater incidence in the placebo group. Events are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are those occurring in at least 1/100 patients, infrequent adverse events are those occurring in between 1/100 and 1/1000 patients, and rare adverse events are those occurring in fewer than 1/1000 patients.

Central and peripheral nervous system: Frequent: dysesthesia and hypoesthesia. Infrequent: tremor, hyperesthesia, migraine aggravated, involuntary muscle contractions, vertigo, ataxia, abnormal gait and speech disorder. Rare: hypertonia, hypotonia, abnormal reflexes and tongue paralysis.

Gastrointestinal: Frequent: vomiting, abdominal pain and diarrhea. Infrequent: dysphagia, flatulence, constipation, anorexia, esophagospasm and saliva increased. Rare: change in bowel habits, cheilitis, eructation, gastroesophageal reflux, hiccup, peptic ulcer, salivary gland pain, stomatitis and toothache.

Body as a whole: Frequent: pain. Infrequent: asthenia, rigors, fever, hot flushes and malaise. Rare: feeling of relaxation, leg pain and edema mouth.

Psychiatric: Frequent: insomnia and anxiety. Infrequent: confusion, nervousness, agitation, euphoria, impaired concentration, depression, emotional lability, amnesia, thinking abnormal and depersonalization. Rare: depression aggravated, abnormal dreaming and personality disorder.

Musculoskeletal: Infrequent: myalgia, back pain, arthralgia, arthrosis, leg cramps and muscle weakness. 

Respiratory: Frequent: sinusitis and rhinitis. Infrequent: pharyngitis, dyspnea, hyperventilation and laryngitis. 

Vision disorders: Frequent: vision abnormal. Infrequent: eye pain, conjunctivitis and abnormal lacrimation.

Skin and appendages: Frequent: sweating increased. Infrequent: pruritis, and bullous eruption.

Hearing and vestibular disorders: Frequent: tinnitus. Infrequent: ear ache, and hyperacusis. 

Heart rate and rhythm: Frequent: palpitation. Infrequent: tachycardia. Rare: bradycardia. 

Metabolic and nutritional disorders: Infrequent: thirst and dehydration. Rare: hypocalcemia and hypoglycemia. 

Special senses, other disorders: Infrequent: taste perversion. 

Urinary system disorders: Infrequent: micturition frequency and polyuria. Rare: nocturia, renal pain and abnormal urine. 

Cardiovascular disorders, general: Infrequent: abnormal ECG.

Platelet, bleeding and clotting disorders: Infrequent: epistaxis. Rare: purpura.

Autonomic nervous system: Rare: syncope.