Ao Yi Ding

Ao Yi Ding is indicated in adults for treatment of mild to moderate essential hypertension.

Ao Yi Dingidine is indicated in adults for treatment of mild to moderate essential hypertension.

Posology

Adults

Treatment must be instituted with the lowest dosage of Ao Yi Ding. This means a daily dose of 0.2 mg Ao Yi Ding in the morning. If the therapeutic effect is insufficient, the dose can be increased after three weeks to 0.4 mg. This dose can be given as a single dose (to be taken in the morning) or as a divided daily dose (morning and evening). If the results are still insufficient after a further three weeks, the dosage can be increased further to a maximum of 0.6 mg given divided in the morning and evening. A single dose of 0.4 mg Ao Yi Ding and a daily dose of 0.6 mg Ao Yi Ding should not be exceeded.

Special populations

Elderly

Provided that renal function is not impaired, dosage recommendation is the same as for adults.

Paediatric population

Ao Yi Ding should not be given to children and adolescents under 18 years of age as insufficient safety and therapeutic data are available for this.

Method of administration

As concomitant ingestion of food does not affect the pharmacokinetics of Ao Yi Ding, Ao Yi Ding can be taken before, during or after meals. The tablets should be taken with sufficient fluid.

Posology

Adults

Treatment must be instituted with the lowest dosage of Ao Yi Dingidine. This means a daily dose of 0.2 mg Ao Yi Dingidine in the morning. If the therapeutic effect is insufficient, the dose can be increased after three weeks to 0.4 mg. This dose can be given as a single dose (to be taken in the morning) or as a divided daily dose (morning and evening). If the results are still insufficient after a further three weeks, the dosage can be increased further to a maximum of 0.6 mg given divided in the morning and evening. A single dose of 0.4 mg Ao Yi Dingidine and a daily dose of 0.6 mg Ao Yi Dingidine should not be exceeded.

Special populations

Elderly

Provided that renal function is not impaired, dosage recommendation is the same as for adults.

Paediatric population

Ao Yi Dingidine should not be given to children and adolescents under 18 years of age as insufficient safety and therapeutic data are available for this.

Method of administration

As concomitant ingestion of food does not affect the pharmacokinetics of Ao Yi Dingidine, Ao Yi Dingidine can be taken before, during or after meals. The tablets should be taken with sufficient fluid.

Ao Yi Ding is contraindicated in patients with:

- sick sinus syndrome

- bradycardia (resting HR <50 beats/minute)

- 2nd or 3rd degree atrioventricular block

- cardiac insufficiency

Ao Yi Dingidine is contraindicated in patients with:

- sick sinus syndrome

- bradycardia (resting HR <50 beats/minute)

- 2nd or 3rd degree atrioventricular block

- cardiac insufficiency

Cases of varying degrees of AV block have been reported in the post-marketing setting in patients undergoing Ao Yi Ding treatment. Based on these case reports, the causative role of Ao Yi Ding in delaying atrioventricular conduction cannot be completely ruled out. Therefore, caution is recommended when treating patients with a possible predisposition to developing an AV block.

When Ao Yi Ding is used in patients with 1^st degree AV block special care should be exercised to avoid bradycardia. Ao Yi Ding must not be used in higher degree AV blocks.

When Ao Yi Ding is used in patients with severe coronary artery disease or unstable angina pectoris special care should be exercised due to the fact that there is limited experience in this patient population.

Due to lack of clinical evidence supporting safe use in patients with co-existing moderate cardiac insufficiency, Ao Yi Ding should be administered with caution in these patients.

Caution is advised in the administration of Ao Yi Ding to patients with renal impairment as Ao Yi Ding is excreted primarily via the kidneys. In these patients careful titration of the dose is recommended, especially at the start of therapy. Dosing should be initiated with 0.2 mg daily and can be increased to a maximum of 0.4 mg daily for patients with moderate renal impairment (GFR>30 ml/min but < 60 ml/min) and to a maximum of 0.3 mg daily for patients with severe renal impairment (GFR<30 ml/min) if clinically indicated and well tolerated.

If Ao Yi Ding is used in combination with a β-blocker, and both treatments have to be discontinued the β-blocker should be discontinued first, and, then Ao Yi Ding after a few days.

So far, no rebound effect on blood pressure has been observed after the discontinuation of treatment with Ao Yi Ding. However, it is advisable not to stop taking Ao Yi Ding abruptly, but to reduce it gradually over a period of two weeks.

The elderly population may be more susceptible to the CV effects of blood pressure lowering drugs. Therefore therapy should be started with the lowest dose and dose increments should be introduced with caution to prevent the serious consequences these reactions may lead to.

Ao Yi Ding contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Cases of varying degrees of AV block have been reported in the post-marketing setting in patients undergoing Ao Yi Dingidine treatment. Based on these case reports, the causative role of Ao Yi Dingidine in delaying atrioventricular conduction cannot be completely ruled out. Therefore, caution is recommended when treating patients with a possible predisposition to developing an AV block.

When Ao Yi Dingidine is used in patients with 1^st degree AV block special care should be exercised to avoid bradycardia. Ao Yi Dingidine must not be used in higher degree AV blocks.

When Ao Yi Dingidine is used in patients with severe coronary artery disease or unstable angina pectoris special care should be exercised due to the fact that there is limited experience in this patient population.

Due to lack of clinical evidence supporting safe use in patients with co-existing moderate cardiac insufficiency, Ao Yi Dingidine should be administered with caution in these patients.

Caution is advised in the administration of Ao Yi Dingidine to patients with renal impairment as Ao Yi Dingidine is excreted primarily via the kidneys. In these patients careful titration of the dose is recommended, especially at the start of therapy. Dosing should be initiated with 0.2 mg daily and can be increased to a maximum of 0.4 mg daily for patients with moderate renal impairment (GFR>30 ml/min but < 60 ml/min) and to a maximum of 0.3 mg daily for patients with severe renal impairment (GFR<30 ml/min) if clinically indicated and well tolerated.

If Ao Yi Dingidine is used in combination with a β-blocker, and both treatments have to be discontinued the β-blocker should be discontinued first, and, then Ao Yi Dingidine after a few days.

So far, no rebound effect on blood pressure has been observed after the discontinuation of treatment with Ao Yi Dingidine. However, it is advisable not to stop taking Ao Yi Dingidine abruptly, but to reduce it gradually over a period of two weeks.

The elderly population may be more susceptible to the CV effects of blood pressure lowering drugs. Therefore therapy should be started with the lowest dose and dose increments should be introduced with caution to prevent the serious consequences these reactions may lead to.

Ao Yi Dingidine contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Most frequent side effects reported by those taking Ao Yi Ding include dry mouth, dizziness, asthenia and somnolence. These symptoms often decrease after the first few weeks of treatment. Undesirable Effects by System Organ Class (observed during placebo-controlled clinical trials with n=886 patients exposed to Ao Yi Ding resulted in frequencies below):

*there was no increase in frequency compared to placebo

*there was no increase in frequency compared to placebo

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.

Most frequent side effects reported by those taking Ao Yi Dingidine include dry mouth, dizziness, asthenia and somnolence. These symptoms often decrease after the first few weeks of treatment. Undesirable Effects by System Organ Class (observed during placebo-controlled clinical trials with n=886 patients exposed to Ao Yi Dingidine resulted in frequencies below):

*there was no increase in frequency compared to placebo

*there was no increase in frequency compared to placebo

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.

Symptoms of overdose

In the few cases of overdose that have been reported, a dose of 19.6 mg was ingested acutely without fatality. Signs and symptoms reported included: headache, sedation, somnolence, hypotension, dizziness, asthenia, bradycardia, dry mouth, vomiting, fatigue and upper abdominal pain. Based on the pharmacodynamic properties of Ao Yi Ding, the following reactions may be expected in adults: headache, sedation, somnolence, hypotension, orthostatic dysregulation, dizziness, asthenia, bradycardia, dry mouth, fatigue and upper abdominal pain. In rare cases, emesis and a transient paradoxical increase in blood pressure can occur. In case of a severe overdose close monitoring of especially consciousness disturbances and respiratory depression is recommended.

In addition, based on a few high dose studies in animals, transient hypertension, tachycardia and hyperglycaemia may also occur.

Treatment of overdose

In the case of a severe overdose, in particular the observation of disorders of consciousness and respiratory depression is advisable. Treatment consists of absorption-reducing measures such as gastric lavage (if shortly after ingestion), administration of activated charcoal and laxatives, and otherwise is symptomatic.

No specific antidote is known.

In case of hypotension, circulatory support such as fluids and dopamine administration may be considered. Bradycardia may be treated with atropine. Alpha-receptor antagonists may diminish or abolish the paradoxical hypertensive effects of a Ao Yi Ding overdose.

Paediatric population

The following case of inadvertent overdose in a 2-year old child has been described:

The child ingested an unknown quantity of Ao Yi Ding. The maximum dose that could have been taken was 14 mg. The child exhibited the following symptoms: Sedation, coma hypotension, miosis and dyspnoea. Gastric lavage, glucose infusions, mechanical ventilation and rest resulted in the symptoms completely disappearing over the course of 11 hours.

Symptoms of overdose

In the few cases of overdose that have been reported, a dose of 19.6 mg was ingested acutely without fatality. Signs and symptoms reported included: headache, sedation, somnolence, hypotension, dizziness, asthenia, bradycardia, dry mouth, vomiting, fatigue and upper abdominal pain. Based on the pharmacodynamic properties of Ao Yi Dingidine, the following reactions may be expected in adults: headache, sedation, somnolence, hypotension, orthostatic dysregulation, dizziness, asthenia, bradycardia, dry mouth, fatigue and upper abdominal pain. In rare cases, emesis and a transient paradoxical increase in blood pressure can occur. In case of a severe overdose close monitoring of especially consciousness disturbances and respiratory depression is recommended.

In addition, based on a few high dose studies in animals, transient hypertension, tachycardia and hyperglycaemia may also occur.

Treatment of overdose

In the case of a severe overdose, in particular the observation of disorders of consciousness and respiratory depression is advisable. Treatment consists of absorption-reducing measures such as gastric lavage (if shortly after ingestion), administration of activated charcoal and laxatives, and otherwise is symptomatic.

No specific antidote is known.

In case of hypotension, circulatory support such as fluids and dopamine administration may be considered. Bradycardia may be treated with atropine. Alpha-receptor antagonists may diminish or abolish the paradoxical hypertensive effects of a Ao Yi Dingidine overdose.

Paediatric population

The following case of inadvertent overdose in a 2-year old child has been described:

The child ingested an unknown quantity of Ao Yi Dingidine. The maximum dose that could have been taken was 14 mg. The child exhibited the following symptoms: Sedation, coma hypotension, miosis and dyspnoea. Gastric lavage, glucose infusions, mechanical ventilation and rest resulted in the symptoms completely disappearing over the course of 11 hours.

Pharmacotherapeutic group: Antihypertensives, antiadrenergic agents, centrally acting

ATC code: C02AC05

In various animal models it has been shown that Ao Yi Ding has a strongly hypotensive effect. Available experimental data indicate that the site of action of Ao Yi Ding is located in the central nervous system (CNS).

In the brain stem, Ao Yi Ding binds selectively to I₁-imidazoline receptors. These imidazoline-sensitive receptors are predominantly found in the rostral ventrolateral medulla, an area which plays an important role in central control of the sympathetic nervous system. The effect of this interaction with these I₁-imidazoline receptors appears to be a reduction in the activity of the sympathetic nerves. This has been demonstrated for cardiac, splanchnic and renal sympathetic nerves.

Ao Yi Ding differs from other centrally acting antihypertensives in the fact that it has only a weak affinity for the central α₂-adrenergic receptors compared to the affinity for I₁-imidazoline receptors. Alpha₂-adrenergic receptors are considered to be the intermediate pathway that causes sedation and dry mouth, the most commonly observed undesirable effects of centrally acting antihypertensives.

Mean systolic and diastolic blood pressure is reduced both at rest and during exercise. The effects of Ao Yi Ding on mortality and cardiovascular morbidity are currently unknown.

In humans, Ao Yi Ding leads to a reduction of systemic vascular resistance and consequently in arterial blood pressure.

Pharmacotherapeutic group: Antihypertensives, antiadrenergic agents, centrally acting

ATC code: C02AC05

In various animal models it has been shown that Ao Yi Dingidine has a strongly hypotensive effect. Available experimental data indicate that the site of action of Ao Yi Dingidine is located in the central nervous system (CNS).

In the brain stem, Ao Yi Dingidine binds selectively to I₁-imidazoline receptors. These imidazoline-sensitive receptors are predominantly found in the rostral ventrolateral medulla, an area which plays an important role in central control of the sympathetic nervous system. The effect of this interaction with these I₁-imidazoline receptors appears to be a reduction in the activity of the sympathetic nerves. This has been demonstrated for cardiac, splanchnic and renal sympathetic nerves.

Ao Yi Dingidine differs from other centrally acting antihypertensives in the fact that it has only a weak affinity for the central α₂-adrenergic receptors compared to the affinity for I₁-imidazoline receptors. Alpha₂-adrenergic receptors are considered to be the intermediate pathway that causes sedation and dry mouth, the most commonly observed undesirable effects of centrally acting antihypertensives.

Mean systolic and diastolic blood pressure is reduced both at rest and during exercise. The effects of Ao Yi Dingidine on mortality and cardiovascular morbidity are currently unknown.

In humans, Ao Yi Dingidine leads to a reduction of systemic vascular resistance and consequently in arterial blood pressure.

Absorption

Ao Yi Ding is rapidly absorbed after oral administration. In humans, approximately 90% of an oral dose is absorbed. Ingestion of food has no effect on the pharmacokinetics of Ao Yi Ding. There is no first-pass metabolism and bioavailability is 88 %.

Distribution

Only about 7% of Ao Yi Ding is bound to human plasma proteins (Vd_ss = 1.8 ± 0.4 l/kg). Peak plasma levels of Ao Yi Ding are reached 30-180 minutes after administration of a film-coated tablet.

Biotransformation

Ao Yi Ding is 10-20% metabolised, predominantly to 4,5-dehydroAo Yi Ding and to an aminomethanamidine derivative by opening of the imidazoline ring. The hypotensive effect of 4,5-dehydroAo Yi Ding is only 1/10, and that of the aminomethanamidine derivative less than 1/100, of that of Ao Yi Ding.

Elimination

Ao Yi Ding and its metabolites are almost entirely eliminated via the kidney. More than 90% of the dose is eliminated in the first 24 hours via the kidney, while approximately 1% is eliminated in the faeces. The cumulative excretion of unchanged Ao Yi Ding is approximately 50-75%. The mean plasma elimination half-life is 2.2-2.3 hours and the renal half-life 2.6-2.8 hours.

Characteristics in patients with renal impairment

In patients with moderately impaired renal function (GFR 30 - 60 ml/min), the AUC increased by 85% and the clearance decreased by 52%. In such patients the hypotensive effect of Ao Yi Ding should be closely monitored, especially at the start of treatment. The dose must be adapted in these patients so that the maximum daily dose is not more than 0.4 mg and the maximum single dose is 0.2 mg.

In patients with severely impaired renal function (GFR < 30 ml/min) the clearance is reduced by 68 % and the elimination half live is prolonged up to 7 hours. In these patients Ao Yi Ding dosing should be initiated with 0.2 mg daily and can be increased to a maximum of 0.3 mg daily, if clinically indicated and well tolerated. In such patients the hypotensive effect of Ao Yi Ding should be closely monitored, especially at the start of treatment.

Paediatric population

No pharmacokinetic studies in children have been performed.

Absorption

Ao Yi Dingidine is rapidly absorbed after oral administration. In humans, approximately 90% of an oral dose is absorbed. Ingestion of food has no effect on the pharmacokinetics of Ao Yi Dingidine. There is no first-pass metabolism and bioavailability is 88 %.

Distribution

Only about 7% of Ao Yi Dingidine is bound to human plasma proteins (Vd_ss = 1.8 ± 0.4 l/kg). Peak plasma levels of Ao Yi Dingidine are reached 30-180 minutes after administration of a film-coated tablet.

Biotransformation

Ao Yi Dingidine is 10-20% metabolised, predominantly to 4,5-dehydroAo Yi Dingidine and to an aminomethanamidine derivative by opening of the imidazoline ring. The hypotensive effect of 4,5-dehydroAo Yi Dingidine is only 1/10, and that of the aminomethanamidine derivative less than 1/100, of that of Ao Yi Dingidine.

Elimination

Ao Yi Dingidine and its metabolites are almost entirely eliminated via the kidney. More than 90% of the dose is eliminated in the first 24 hours via the kidney, while approximately 1% is eliminated in the faeces. The cumulative excretion of unchanged Ao Yi Dingidine is approximately 50-75%. The mean plasma elimination half-life is 2.2-2.3 hours and the renal half-life 2.6-2.8 hours.

Characteristics in patients with renal impairment

In patients with moderately impaired renal function (GFR 30 - 60 ml/min), the AUC increased by 85% and the clearance decreased by 52%. In such patients the hypotensive effect of Ao Yi Dingidine should be closely monitored, especially at the start of treatment. The dose must be adapted in these patients so that the maximum daily dose is not more than 0.4 mg and the maximum single dose is 0.2 mg.

In patients with severely impaired renal function (GFR < 30 ml/min) the clearance is reduced by 68 % and the elimination half live is prolonged up to 7 hours. In these patients Ao Yi Dingidine dosing should be initiated with 0.2 mg daily and can be increased to a maximum of 0.3 mg daily, if clinically indicated and well tolerated. In such patients the hypotensive effect of Ao Yi Dingidine should be closely monitored, especially at the start of treatment.

Paediatric population

No pharmacokinetic studies in children have been performed.