Expected onset of pain relief is rapid with a median onset of 5 minutes
- One 3 mL bottle of PENTHROX® is vaporised in the PENTHROX® Inhaler.
- On finishing the 3 mL dose, another 3 mL may be used, if needed.
- The dose should not exceed 6 mL in a single administration, or over the first day of treatment.
- The frequency at which PENTHROX® treatment can be safely used is not established.
- A maximum daily dose of 6 mL of PENTHROX® should not be administered on any two consecutive days.
- A treatment course of PENTHROX® should be limited to a total doseof 15 mL over one week, with no more than 6 mL to be used in a single 48 hour period.
- Patients should be instructed to inhale intermittently to achieve adequate analgesia. Patients can assess their own level of pain and titrate the amount of PENTHROX® inhaled for adequate pain control.
- Patients should be advised to take the lowest possible dose to achieve pain relief.
- Continuous inhalation provides analgesic relief for up to 25-30 minutes, or approximately 1 hour when administered intermittently.
- Treatment courses of PENTHROX® should not be repeated at an interval of less than 3 months.
Continuous inhalation provides analgesic relief for up
to 25–30 minutes,
or approximately 1 hour when
administered intermittently
Continuous inhalation provides analgesic relief for up to 25–30 minutes, or approximately 1 hour when administered intermittently
CLINICAL USE:
Due to dose limitations of a treatment course of PENTHROX® and the duration of associated pain relief, PENTHROX® is not appropriate for providing relief of break-through pain in chronic pain conditions. PENTHROX® is also not appropriate for relief of repetitive pain. PENTHROX® is not indicated for use during pregnancy or the peripartum period, including labour.
CONTRAINDICATIONS:
• Altered level of consciousness due to any cause
including head injury, drugs, or alcohol
• Clinically
significant renal impairment
• History of liver
dysfunction after previous methoxyflurane use or
other halogenated anesthetics
• Hypersensitivity to
methoxyflurane or any other halogenated
anesthetics
• Known or genetically susceptible to
malignant hyperthermia or a history of severe adverse
reactions in either patient or relatives
•
Clinically evident hemodynamic instability
•
Clinically evident respiratory impairment
• Use as an
anesthetic agent
MOST SERIOUS WARNINGS AND PRECAUTIONS:
Nephrotoxicity: Supratherapeutic doses of methoxyflurane inhalation have been shown to lead to serious, irreversible nephrotoxicity in a dose-related manner. Dosing limitations should be followed meticulously to prevent or limit risk of nephrotoxicity. Consecutive day use of PENTHROX® is not recommended because of nephrotoxic potential. The lowest effective dose should be administered, especially in the elderly or in patients with other known risk factors of renal disease.
Hepatotoxicity: Very rare cases of hepatotoxicity have been reported with methoxyflurane inhalation when used for analgesic purposes. Use with care in patients with underlying hepatic conditions or having risk factors for hepatic dysfunction. PENTHROX® must not be used in patients who have a history of showing signs of liver damage after previous methoxyflurane use or halogenated hydrocarbon anesthesia.
OTHER RELEVANT WARNINGS AND PRECAUTIONS:
• Potential CNS effects
• Administer with caution in
elderly patients with hypotension and bradycardia due to
possible reduction in blood pressure
• Drug
dependence
• May influence the ability to drive and
operate machinery
• Do not administer concomitantly
with alcohol ingestion
• To reduce occupational
exposure to methoxyflurane, the PENTHROX®
Inhaler should always be used with the activated carbon
chamber to adsorb exhaled methoxyflurane
• Local skin
reactions or irritation to the eyes and mucous
membranes
• Exercise caution if administering to a
nursing mother
FOR MORE INFORMATION:
Please consult the Product Monograph at https://health-products.canada.ca/dpd-bdpp/index-eng.jsp for important information relating to adverse reactions, drug interactions, patient counselling, and dosing/ disposal information (regarding the total maximum dose for a single administration or over the first day of treatment, in a single 48-hour period and entire treatment course) which have not been discussed in this piece.
The Product Monograph is also available by calling us at 1-888-867-7426.
† Comparative clinical significance unknown.
*Clinical significance unknown
REFERENCES:
1.
PENTHROX®Product
Monograph,
Paladin
Pharma
Inc.,
April
2022.
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SG,
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TRUS-GUIDED
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7.
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Brichko
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