Merron

Merrone is used for the control of vestibular disorders such as vertigo, tinnitus, nausea and vomiting such as that seen in Meniere's disease.

Merrone is also effective in the control of motion sickness.

Merron is for the control of vestibular disorders such as vertigo, tinnitus, nausea and vomiting such as is seen in Meniere's Disease.

Merron is also effective in the control of motion sickness.

Posology

Vestibular symptoms:

Adults, elderly and children over 12 years:

Two tablets three times a day.

Children 5-12 years:

One tablet three times a day.

The stated doses should not be exceeded.

Motion sickness:

Adults, elderly and children over 12 years:

Two tablets two hours before travel and one tablet every eight hours during journey if necessary.

Children 5-12 years:

One tablet two hours before travel and half a tablet every eight hours during journey if necessary.

Method of administration

For oral use.

Merrone should preferably be taken after meals. The tablets may be sucked, chewed or swallowed whole with water.

Method of administration

Oral. The tablets may be chewed, sucked or swallowed whole.

Posology

Merron should preferably be taken after meals.

Vestibular symptoms

Adults, elderly and children over 12 years: 2 tablets three times a day.

Children 5 to 12 years: One half the adult dose.

These doses should not be exceeded.

Motion sickness

Adults, elderly and children over 12 years: 2 tablets 2 hours before you travel and 1 tablet every 8 hours during your journey.

Children 5 to 12 years: One half the adult dose.

Merron should not be given to patients with known hypersensitivity to cinnarizine.

As with other antihistamines, Merrone may cause epigastric discomfort; taking it after meals may diminish gastric irritation. Merrone should only be given to patients with Parkinson's disease if the advantages outweigh the possible risk of aggravating this disease.

Use of Merrone should be avoided in porphyria.

There have been no specific studies in hepatic or renal dysfunction. Merrone should be used with care in patients with hepatic or renal insufficiency.

Merrone Tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

As with other antihistamines, Merron may cause epigastric discomfort; taking it after meals may diminish the gastric irritation.

In patients with Parkinson's Disease, Merron should only be given if the advantages outweigh the possible risk of aggravating this disease.

Because of its antihistamine effect, Merron may prevent an otherwise positive reaction to dermal reactivity indicators if used within 4 days prior to testing.

Use of cinnarizine should be avoided in porphyria.

There have been no specific studies in hepatic or renal dysfunction. Merron should be used with care in patients with hepatic or renal insufficiency.

Patients with rare hereditary problems of fructose or galactose intolerance, Lapp lactase deficiency, glucose-galactose malabsorption or sucrase-isomaltase insufficiency, should not take this medicine because it contains lactose and sucrose.

Merrone may cause drowsiness, especially at the start of treatment; patients affected in this way should not drive or operate machinery.

Merron may cause drowsiness, especially at the start of treatment; patients affected in this way should not drive or operate machinery.

The safety of Merrone was evaluated in 372 Merrone-treated subjects who participated in 7 placebo-controlled trials for the indications peripheral circulatory disorders, cerebral circulatory disorders, vertigo and seasickness; and in 668 Merrone treated subjects who participated in six comparator and thirteen open label clinical trials for the indications peripheral circulatory disorders, cerebral circulatory disorders and vertigo. Based on pooled safety data from these clinical trials, the most commonly reported (>2% incidence) adverse drug reactions (ADRs) were: somnolence (8.3) and weight increased (2.1).

Including the above mentioned ADRs, the following ADRs have been observed from clinical trials and post-marketing experiences reported with the use of Merrone. Frequencies displayed use the following convention:

Very common (> 1/10); common (> 1/100 to < 1/10); uncommon (> 1/1,000 to < 1/100); rare (> 1/10,000 to <1/1,000); very rare (<1/10,000) and not known (cannot be estimated from the available data).

Cases of hypersensitivity, headache and dry mouth have also been reported.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.

The safety of Merron was evaluated in 372 cinnarizine-treated subjects who participated in 7 placebo-controlled trials for the indications peripheral circulatory disorders, cerebral circulatory disorders, vertigo and seasickness; and in 668 cinnarizine-treated subjects who participated in six comparator and thirteen open label clinical trials for the indications peripheral circulatory disorders, cerebral circulatory disorders and vertigo. Based on pooled safety data from these clinical trials, the most commonly reported (>2% incidence) Adverse Drug Reactions (ADRs) were: somnolence (8.3) and weight increased (2.1).

Including the above mentioned ADRs, the following ADRs have been observed from clinical trials and post-marketing experiences reported with the use of Merron. Frequencies displayed use the following convention:

Very common (> 1/10); common (> 1/100 to < 1/10); uncommon (> 1/1,000 to < 1/100); rare (> 1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be estimated from the available data).

Cases of hypersensitivity, headache and dry mouth have been reported.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Symptoms

The signs and symptoms are mainly due to the anticholinergic (atropine-like) activity of Merrone.

Acute Merrone overdoses have been reported with doses ranging from 90 to 2,250 mg. Vomiting, alterations in consciousness ranging from somnolence to stupor and coma, extrapyramidal symptoms and hypotonia are the most commonly reported signs and symptoms associated with a Merrone overdose. In a small number of young children, seizures developed. Clinical consequences were not severe in most cases, but deaths have been reported after single and polydrug overdoses involving Merrone.

Treatment

There is no specific antidote to Merrone and in the event of overdosage, treatment is symptomatic and supportive care. The administration of activated charcoal should only be considered in patients presenting within one hour of taking a potentially toxic overdose (i.e. more than 15 mg/kg).

Symptoms

The signs and symptoms are mainly due to the anticholinergic (atropine-like) activity of cinnarizine.

Acute cinnarizine overdoses have been reported with doses ranging from 90 to 2,250 mg. The most commonly reported signs and symptoms associated with overdose of cinnarizine include: alterations in consciousness ranging from somnolence to stupor and coma, vomiting, extrapyramidal symptoms, and hypotonia. In a small number of young children, seizures developed. Clinical consequences were not severe in most cases, but deaths have been reported after single and polydrug overdoses involving cinnarizine.

Treatment

There is no specific antidote. For any overdose, the treatment is symptomatic and supportive care.

It is advisable to contact a poison control center to obtain the latest recommendations for the management of an overdose.

Pharmacotherapeutic group: Antivertigo preparations, ATC code: N07CA02.

Mechanism of action

Merrone is a piperazine derivative with the actions and uses of the antihistamines.

Merrone has been shown to be a non-competitive antagonist of the smooth muscle contractions caused by various vasoactive agents including histamine. It acts on smooth muscle by selectively inhibiting the transport of calcium ions across cell membranes into depolarised cells, therefore reducing the availability of free Ca⁺ ions for the induction and maintenance of contraction.

Pharmacodynamic effects

Vestibular eye reflexes induced by caloric stimulation of the labyrinth in guinea pigs are markedly depressed by Merrone.

Merrone has been shown to inhibit nystagmus.

ATC Code N07CA02.

Cinnarizine has been shown to be a non-competitive antagonist of the smooth muscle contractions caused by various vasoactive agents including histamine.

Cinnarizine also acts on vascular smooth muscle by selectively inhibiting the calcium influx into depolarised cells, thereby reducing the availability of free Ca²⁺ ions for the induction and maintenance of contraction.

Vestibular eye reflexes induced by caloric stimulation of the labyrinth in guinea pigs are markedly depressed by cinnarizine.

Cinnarizine has been shown to inhibit nystagmus.

Absorption

In man, after oral administration, absorption is relatively slow, peak serum concentrations occurring after 2.5 to 4 hours.

Distribution

The plasma protein binding of Merrone is 91%

Biotransformation

In animals, Merrone is extensively metabolised, N-dealkylation being the major pathway.

Merrone undergoes extensive metabolism mainly via CYP2D6 but there is considerable interindividual variation in the extent of metabolism.

Elimination

Approximately two thirds of the metabolites are excreted with the faeces, the rest in the urine (unchanged as metabolites and glucuronide conjugates), mainly during the first five days after a single dose.

The reported elimination half-life for Merrone ranges from 4 to 24 hours.

In animals, cinnarizine is extensively metabolised, N-dealkylation being the major pathway. Approximately two thirds of the metabolites are excreted with the faeces, the rest in the urine, mainly during the first five days after a single dose.

Absorption

In man, after oral administration, absorption is relatively slow, peak serum concentrations occurring after 2.5 to 4 hours.

Distribution

The plasma protein binding of cinnarizine is 91%.

Metabolism

Cinnarizine is extensively metabolised mainly via CYP2D6, but there is considerable interindividual variation in the extent of metabolism.

Elimination

The reported elimination half-life for cinnarizine ranges from 4 to 24 hours.

The elimination of metabolites occurs as follows: one third in the urine (unchanged as metabolites and glucuronide conjugates) and two thirds in the faeces.

Nonclinical safety studies showed that effects were observed only after chronic exposures from approximately 7 to 35 times the recommended maximum daily human dose of 90 mg/day calculated on a body surface area basis. Merrone blocked the cardiac hERG channel in vitro, however in isolated cardiac tissue and following intravenous application in guinea-pigs, no QTc prolongation or proarrhythmic effects were observed at substantially higher exposures than those expected clinically.

In reproductive studies in the rat, rabbit, and dog, there was no evidence of adverse effects on fertility and no teratogenicity. At high doses associated with maternal toxicity in the rat there was a decreased litter size, an increase in resorptions and a decrease in foetal birth weight.

In vitro mutagenicity studies indicated that the parent compound is not mutagenic however, after reacting with nitrite and forming the nitrosation product, a weak mutagenic activity was observed. Carcinogenicity studies have not been conducted however, no pre-neoplastic changes were evident during chronic 18-month oral administration in rats up to approximately 35 times the maximum human dose level.

Nonclinical safety studies showed that effects were observed only after chronic exposures from approximately 7 to 35 times the recommended maximum daily human dose of 90 mg/day calculated on a body surface area basis. Cinnarizine blocked the cardiac hERG channel in vitro, however in isolated cardiac tissue and following intravenous application in guinea-pigs, no QTc prolongation or proarrhythmic effects were observed at substantially higher exposures than those expected clinically.

In reproductive studies in the rat, rabbit, and dog, there was no evidence of adverse effects on fertility and no teratogenicity. At high doses associated with maternal toxicity in the rat there was a decreased litter size, an increase in resorptions and a decrease in fetal birth weight.

In vitro mutagenicity studies indicated that the parent compound is not mutagenic however, after reacting with nitrite and forming the nitrosation product, a weak mutagenic activity was observed. Carcinogenicity studies have not been conducted however, no pre-neoplastic changes were evident during chronic 18-month oral administration in rats up to approximately 35 times the maximum human dose level.

Not applicable

None known.

No special requirements

No special requirements.