Green film coated, D shaped, biconvex tablets engraved GX CE5 on one face. Each tablet contains 2.5mg of naratriptan as naratriptan hydrochloride.
Naramig Tablets are indicated for the acute treatment of migraine attacks with or without aura.
Naramig Tablets should be taken as early as possible after the onset of a migraine headache but they are effective if taken at a later stage. Naramig Tablets should not be used prophylactically. Naramig Tablets should be swallowed whole with water. Adults (18-65 years of age):- The recommended dose of Naramig Tablets is a single 2.5mg tablet. The total dose should not exceed two 2.5mg tablets in any 24 hour period. If symptoms of migraine should recur, following an initial response, a second dose may be taken provided that there is a minimum interval of four hours between the two doses. If a patient does not respond to the first dose of Naramig Tablets it is unlikely that a second dose will be of benefit in the same attack. Naramig Tablets may be used for subsequent migraine attacks.
Adolescents (12-17 years of age):-
In a clinical trial in adolescents, a very high placebo response was observed. The efficacy of naratriptan in this population has therefore not been demonstrated and its use cannot be recommended.
Children (under 12 years of age):-
There are no data available on the use of naratriptan in children under 12 years of age therefore its use in this age group is not recommended.
Elderly (over 65 years of age):-
The safety and effectiveness of naratriptan in individuals over age 65 have not been evaluated. There is a moderate decrease in clearance with age (see Pharmacokinetic Properties).
Renal Impairment:-
The maximum total daily dose in patients with renal impairment is a single 2.5mg tablet. The use of naratriptan is contraindicated in patients with severe renal impairment (creatinine clearance < 15mL/min). (See Contra-indications and Pharmacokinetic Properties).
Hepatic Impairment:-
The maximum total daily dose in patients with hepatic impairment is a single 2.5mg tablet. The use of naratriptan is contraindicated in patients with severe hepatic impairment (Child-Pugh grade C). (See Contra-indications and Pharmacokinetic Properties).
Hypersensitivity to any component of the preparation. Naratriptan should not be used in patients who have had a myocardial infarction or have ischaemic heart disease, or Prinzmetal's angina/coronary vasospasm, peripheral vascular disease or patients who have symptoms or signs consistent with ischaemic heart disease. Naratriptan should not be administered to patients with a history of cerebrovascular accident (CVA) or transient ischaemic attack (TIA). The use of naratriptan in patients with uncontrolled hypertension is contraindicated. Naratriptan is contraindicated in patients with severely impaired renal or hepatic function.
Naratriptan should only be used where there is a clear diagnosis of migraine. Naratriptan is not indicated for use in the management of hemiplegic, basilar or ophthalmoplegic migraine. As with other acute migraine therapies, before treating headaches in patients not previously diagnosed as migraineurs, and in migraineurs who present with atypical symptoms, care should be taken to exclude other potentially serious neurological conditions. It should be noted that migraineurs may be at risk of certain cerebrovascular events (eg. CVA or TIA). As with other 5-hydroxytryptamine1 (5-HT1) receptor agonists, naratriptan should not be given to patients in whom unrecognised cardiac disease is likely without a prior evaluation for underlying cardiovascular disease. Such patients include postmenopausal women, males over 40 and patients with risk factors for coronary artery disease. If symptoms consistent with ischaemic heart disease occur appropriate evaluation should be carried (see Undesirable Effects). Serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) has been reported following concomitant treatment with triptans and selective serotonin reuptake inhibitors (SSRIs)/serotonin noradrenaline reuptake inhibitors (SNRIs). If concomitant treatment with naratriptan and an SSRI/SNRI is clinically warranted, appropriate observation of the patient is advised (see Interaction with Other Medicinal Products). The concomitant administration of ergotamine, derivatives of ergotamine (including methysergide) and any triptan/5-HT1 agonist with naratriptan is not recommended. However, co-administration of naratriptan with ergotamine, dihydroergotamine, or sumatriptan did not result in clinically relevant effects on blood pressure, heart rate or ECG or affect naratriptan exposure. Naratriptan contains a sulphonamide component therefore there is a theoretical risk of a hypersensitivity reaction in patients with known hypersensitivity to sulphonamides. The recommended dose of naratriptan should not be exceeded. Overuse of acute migraine treatments has been associated with the exacerbation of headache (medication overuse headache, MOH) in susceptible patients. Withdrawl of the treatment may be necessary.
Use in Pregnancy
The safe use of naratriptan in pregnant women has not been established. Evaluation of experimental animal studies does not indicate any direct teratogenic effects or harmful effects on peri- and postnatal development. Because animal reproduction studies are not always predictive of human response administration of naratriptan should only be considered if the expected benefit to the mother is greater than any possible risk to the foetus.
Use in Lactation
Naratriptan and/or drug related metabolites are secreted into the milk of lactating rats. Caution should be exercised when considering administration of naratriptan to nursing women.
Effects on Ability to Drive and Use Machines
Drowsiness may occur as a result of migraine or its treatment with Naramig. Caution is recommended when skilled tasks are to be performed e.g. driving or operating machinery.
Other
Preclinical safety data
No clinically relevant findings were observed in preclinical studies.
Adverse events are listed below by system organ class and frequency. Frequencies are defined as: very common (>1/10), common (>1/100, <1/10), uncommon (>1/1000, <1/100), rare (>1/10,000, <1/1000), and very rare (<1/10,000). Common and uncommon frequencies were determined from clinical trial data. Very rare frequencies were generally derived from spontaneous data.
Clinical Trial Data Nervous system disorders
Common:Tingling
This is usually of short duration, may be severe and may affect any part of the body including the chest or throat.
Gastrointestinal
Common:Nausea and vomiting Occurred in some patients but the relationship to naratriptan is not clear.
Musculoskeletal and connective disorders
Uncommon:Sensations of heaviness . This is usually of short duration, may be severe and may affect any part of the body including the chest or throat.
General disorders and administration site conditions
The following symptoms are usually of short duration, may be severe and may affect any part of the body including the chest or throat: Common:Pain and sensations of heat. Uncommon:Sensations of pressure or tightness.
Postmarketing Data Immune system disorders
Rare:Hypersensitivity reactions ranging from cutaneous hypersensitivity to cases of anaphylaxis
Nervous system disorders
Rare:Somnolence
Cardiac disorders
Very rare:Coronary artery vasospasm, transient ischaemic ECG changes, angina and myocardial infarctions (see Contra-indications and Special Warnings and Special Precautions for Use).
Vascular disorders
Very rare:Peripheral vascular ischaemia.
Gastrointestinal disorders
Very rare:Ischaemic colitis.
Serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) has been reported following concomitant treatment with triptans and SSRIs/SNRIs(see Special Warnings and Special Precautions for Use). There is no evidence of a pharmacokinetic interaction between naratriptan and b-blockers, tricyclic antidepressants, selective serotonin reuptake inhibitors, alcohol or food. Naratriptan does not inhibit monoamine oxidase enzymes; therefore interactions with monoamine oxidase inhibitors are not anticipated. In addition, the limited metabolism of naratriptan and the wide range of cytochrome P450 isoenzymes involved suggest that significant drug interactions with naratriptan are unlikely (see Pharmacokinetic Properties).
Administration of a high dose of 25mg naratriptan in one healthy male subject increased blood pressure by up to 71mmHg and resulted in adverse events including light-headedness, tension in the neck, tiredness and a loss of co- ordination. Blood pressure returned to baseline by 8 hours after dosing without other pharmacological intervention. It is unknown what effect haemodialysis or peritoneal dialysis has on the plasma concentrations of naratriptan.
Treatment:-
If overdosage with naratriptan occurs, the patient should be monitored for at least 24 hours and standard supportive treatment applied as required.
Actions
Naratriptan has been shown to be a selective agonist for 5 hydroxytryptamine1 (5-HT1) receptors mediating vascular contraction. This receptor is found predominantly in intracranial (cerebral and dural) blood vessels. Naratriptan has high affinity for human cloned 5-HT1B and 5-HT1D receptors, the human 5-HT1B receptor is thought to correspond to the vascular 5-HT1 receptor mediating contraction of intracranial blood vessels. Naratriptan has little or no effect at other 5-HT receptor (5- HT2, 5-HT3, 5-HT4 and 5-HT7) subtypes. In animals, naratriptan selectively constricts the carotid arterial circulation. This circulation supplies blood to the extracranial and intracranial tissues such as the meninges, and dilatation and/or oedema formation in these vessels is thought to be the underlying mechanism of migraine in man. In addition, experimental evidence suggests that naratriptan inhibits trigeminal nerve activity. Both these actions may contribute to the anti-migraine action of naratriptan in humans.
Pharmacokinetics
Absorption
Following oral administration, naratriptan is rapidly absorbed with maximum plasma concentrations observed at 2-3 hours. After administration of a 2.5mg naratriptan tablet Cmax is approximately 8.3ng/mL (95% CI: 6.5 to 10.5ng/mL) in women and 5.4ng/mL (95% CI: 4.7 to 6.1ng/mL) in men. The oral bioavailability is 74% in women and 63% in men with no differences in efficacy and tolerability in clinical use. Therefore a gender related dose adjustment is not required.
Distribution
Naratriptan is distributed in a volume of 170 litres. Plasma protein binding is low (29%).
Metabolism
Naratriptan is predominantly excreted in the urine with 50% of the dose recovered as unchanged naratriptan and 30% recovered as inactive metabolites. In vitro naratriptan was metabolised by a wide range of cytochrome P450 isoenzymes. Consequently significant metabolic drug interactions with naratriptan are not anticipated (see Interaction with Other Medicinal Products and other Forms of Interaction).
Elimination
The mean elimination half-life (t1/2) is 6 hours. Mean clearance after intravenous administration was 470mL/min in men and 380mL/min in women. Renal clearance is similar in men and women at 220mL/min and is higher than the glomerular filtration rate suggesting that naratriptan is actively secreted in the renal tubules.
Special Patient Populations:-
Elderly:- In healthy elderly subjects (n=12), clearance was decreased by 26% when compared to healthy young subjects (n=12) in the same study (see Posology and Method of Administration). Gender:- The naratriptan AUC and Cmax were approximately 35% lower in males compared to females however, with no differences in efficacy and tolerability in clinical use. Therefore a gender related dose adjustment is not required (see Posology and Method of Administration). Renal Impairment:- Renal excretion is the major route for the elimination of naratriptan. Accordingly exposure to naratriptan may be increased in patients with renal disease. In a study in male and female renally impaired patients (creatinine clearance 18 to 115mL/min; n=15) matched for sex, age and weight with healthy subjects (n=8), renally impaired patients had an approximately 80% increase in t1/2 and an approximately 50% reduction in clearance (see Posology and Method of Administration). Hepatic Impairment:- The liver plays a lesser role in the clearance of orally administered naratriptan. In a study in male and female hepatically impaired patients (Child-Pugh grade A or B n=8) matched for sex, age and weight with healthy subjects who received oral naratriptan, hepatically impaired patients had an approximately 40% increase in t1/2 and an approximately 30% reduction in clearance (see Posology and Method of Administration).
Other
List of Excipients
Tablet core:-
Microcrystalline cellulose. Anhydrous lactose.
Croscarmellose sodium. Magnesium stearate.
Film coat:-
Methylhydroxypropylcellulose. Titanium dioxide (E171).
Triacetin. Iron oxide yellow (E172). Indigo carmine aluminium lake (E132).
Instructions for Use/Handling
None. Incompatibilities None reported.
Shelf Life
36 months.
Special Precautions for Storage
Store below 30C.
Nature and Contents of Container
Double foil blister pack.
2.5 mg tablets: blister strip of 2 tablets.
Prescription Only Medicine
GlaxoSmithKline NZ Limited Quay Tower Cnr Albert & Customs Streets Private Bag 106600 Downtown Auckland NEW ZEALAND Telephone (09) 367 2900 Facsimile (09) 367 2506
Date: 6 September 2013 Version: 2.0 NARAMIG is a trade mark of the GlaxoSmithKline group of companies. (c) This Data Sheet is copyrighted to GlaxoSmithKline and may be reproduced but not altered in any way.