Ampres

/ CTS

The equipment, medicinal products and personnel capable of dealing with an emergency, e.g. maintaining the patency of the airways and administering oxygen, must be immediately available, since in rare cases severe reactions, sometimes with a fatal outcome, have been reported after using local anaesthetics, even in the absence of individual hypersensitivity in the patient’s case history. The doctor in charge is responsible for taking the measures needed to avoid an intravascular injection and should be fully trained in emergency medicine and resuscitation to be ready to prevent and treat the side effects and complication of the procedure.
Posology:
Posology must be established on an individual basis in accordance with the characteristics of the specific case. When determining the dose, the patient’s physical condition and the concomitant administration of other medicinal products should be taken into consideration.
The indications relating to recommended doses are valid in adults of average height and weight (approximately 70 kg) for obtaining an effective block with one single administration. There are wide individual variations with regard to extent and duration of action. The experience of the anaesthetist and knowledge of the patient’s general condition are essential for establishing the dose. The maximum recommended dose is 50mg (=5ml) of chloroprocaine hydrochloride. The duration of action is dose-dependent.
This medicinal product should be injected via intrathecal route into the intervertebral space L2/L3, L3/L4 and L4/L5.
The entire dose should be injected slowly, after having aspirated a minimum quantity of CSF to confirm the correct position. The patient’s vital functions should be checked extremely carefully maintaining continuous verbal contact.
See prescribing information for full details.

Spinal anaesthesia in adults where the planned surgical procedure should not exceed 40 minutes.

– Hypersensitivity to the active substance, medicinal products of the PABA (para-aminobenzoic acid) ester group, other ester-type local anaesthetics or to any of the excipients.
– General and specific contra-indications to spinal anaesthesia regardless of the local anaesthetic used, should be taken into account (e.g. decompensated cardiac insufficiency, hypovolemic shock).
– Intravenous regional anaesthesia (the anesthetic agent is introduced into the limb and allowed to set in while tourniquets retain the agent within the desired area).
− Serious problems with cardiac conduction,
− Severe anaemia.
− Patients taking anticoagulants or with congenital or acquired bleeding disorder.

Some patients require special attention in order to reduce the risk of serious undesirable effects, even when locoregional anaesthesia constitutes the optimum choice for the surgical intervention:
− Patients with total or partial heart block, since local anaesthetics can suppress myocardial conduction.
− Patients with high grade cardiac decompensation.
− Patients with advanced liver or kidney damage.
− Elderly patients and patients in poor general condition.
− Patients treated with class III antiarrhythmic medicinal products (e.g. amiodarone). These patients should be subjected to careful observation and ECG monitoring, since cardiac effects may be added.
− In patients with acute porphyria, Ampres should only be administered when there is a compelling indication for its use, as Ampres may potentially precipitate porphyria. Appropriate precautions should be taken in all patients with porphyria.
− Since ester-type local anaesthetics are hydrolyzed by plasma cholinesterase produced by the liver, chloroprocaine should be used cautiously in patients with advanced hepatic disease.
− Patients with genetic deficiency of plasma cholinesterase.
Ensuring the presence of reliable venous access is mandatory.
In high risk patients, the recommendation is to improve their general condition prior to the intervention.
A rare, but serious, undesirable effect of spinal anaesthesia is high or total spinal block, with consequent cardiovascular and respiratory depression. Cardiovascular depression is induced by an extended block of the sympathetic nervous system, which may induce severe hypotension and bradycardia to the point of cardiac arrest. Respiratory depression is induced by the block of the respiratory musculature and the diaphragm.
Especially in elderly patients there is an increased risk of high or total spinal block: consequently, it is advisable to reduce the anaesthetic dose.
Particularly in the case of elderly patients, an unexpected drop in arterial pressure may occur as a complication of spinal anaesthesia.
Rarely, neurological damage may occur after spinal anaesthesia, manifesting as paresthesia, loss of sensitivity, motor weakness, paralysis, cauda equina syndrome and permanent neurological injury. Occasionally these symptoms persist.
There is no suspicion that neurological disorders, such as multiple sclerosis, hemiplegia, paraplegia or neuromuscular disorders may be negatively influenced by spinal anaesthesia. Nevertheless, it should be used with care. Careful evaluation of the risk-benefit ratio is recommended prior to treatment.
In case of unintentional intravascular injection severe systemic toxicity may occur immediately.
This medicinal product contains less then 1 mmol sodium (23 mg) per dose (maximum dose equal to 5 ml of this medicinal product), that is to say essentially “sodium-free”.

Very common: Hypotension, nausea.
Common: Anesthetic complication, anxiety, restlessness, paresthesia, dizziness, vomiting.

Concurrent administration of vasopressors (eg for the treatment of hypotension related to obstetric blocks) and ergot-type oxytocic medicinal products may cause severe, persistent hypertension or cerebrovascular accidents.
The para-aminobenzoic acid metabolite of chloroprocaine inhibits the action of sulfonamides. Therefore, chloroprocaine should not be used in any condition in which a sulfonamide medicinal products is being employed.
No studies have been performed on interactions between chloroprocaine and class III antiarrhythmics (e.g. amiodarone), but care must also be taken in this case.
The combination of various local anaesthetics induces additional effects which affect the cardiovascular system and the CNS.

Pregnancy:
Animal studies are insufficient with respect to effects on pregnancy and foetal development.
Therefore, Ampres is not recommended during pregnancy and in women of childbearing potential not using contraception. The use of Ampres in pregnancy should only be considered if the expected benefit to the mother outweighs any potential risk to the foetus. This does not preclude the use of Ampres at term for obstetrical anaesthesia.
Breastfeeding:
It is not known whether chloroprocaine/metabolites are excreted in human milk. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Ampres therapy taking into account the benefit of breast feeding for the child and the benefit of therapy for the woman.
Fertility:
No fertility studies the have been performed.

It is unlikely that this medicinal product, at the recommended posology by intrathecal administration, will induce plasma levels capable of inducing systemic toxicity.
Acute systemic toxicity:
Systemic undesirable effects are of methodological (due to use), pharmacodynamic or pharmacokinetic origin and concern the central nervous system and the cardiocirculatory system.
Iatrogenic undesirable effects occur:
− after injecting an excessive quantity of solution
− from accidental injection into a vessel
− from incorrect patient position
− from high spinal anaesthesia (marked drop in arterial pressure)
In the case of accidental intravenous administration, the toxic effect occurs within 1 minute. The intravenous LD50 of chloroprocaine HCl is 97 mg/kg in mice, 65 mg/kg in guinea pigs and <30 mg/kg in dogs, corresponding to human equivalent doses of 7.9 mg/kg, 14.1 mg/kg and < 16.7 mg/kg, respectively. The subcutaneous LD50 of chloroprocaine HCl in mice is 950 mg/kg, corresponding to human equivalent dose of 77.2 mg/kg.
Signs of overdose can be classified into two different sets of symptoms which differ in terms of quality and intensity: symptoms affecting the central nervous system and/or cardiovascular symptoms.
Treatment of acute systemic toxicity:
The following measures must be taken immediately:
− Administration of Ampres must be stopped.
− An adequate supply of oxygen must be ensured: the airways should be kept clear, O2 should be administered, artificial ventilation (intubation) if required.
− In case of cardiovascular depression circulation must be stabilized.
If convulsions occur and do not resolve spontaneously after 15-20 seconds, the administration of an intravenous anticonvulsant is recommended.
Analeptics with a central action are contraindicated in the case of intoxication caused by local anaesthetics!
In the event of serious complications, when treating the patient it is advisable to obtain the assistance of a doctor specializing in emergency medicine and resuscitation (e.g. anaesthetist).
In patients with genetic deficiency of plasma cholinesterase an intravenous lipid solution could be administered.

Do not store above 25°C. Do not refrigerate or freeze. Keep ampoule in the outer carton, in order to protect from light.