Fentanyl

Indications

Fentanyl is used for: Pain, Cancer pain, Anesthesia, Analgesia, Breakthrough pain

Adult Dose

Parental Surgery Premedication 50-100 mcg/dose IM or slow IV 30-60 min prior to surgery Adjunct to regional anesthesia: 25-100 mcg/dose slow IV over 1-2 min General Anesthesia Minor surgical procedures: 0.5-2 mcg/kg/dose IV Major surgery: 2-20 mcg/kg/dose initially; 1-2 mcg/kg/hr maintenance infusion IV; discontinue infusion 30-60 min prior to end of surgery; limit total fentanyl doses to 10-15 mcg/kg for fast tracking and early extubation Adjunct to general anesthesia (rarely used): 20-50 mcg/kg/dose IV Transdermal Chronic Severe Pain Indicated for chronic pain in opioid-tolerant patients, severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate 25-100 mcg/hr, reapplied q72hr until adequate analgesia is achieved. During transfer to fentanyl patches, previous opioid treatment should be phased out gradually. If patient requires doses >100 mcg/hr, >1 patch may be used; consider alternative or additional therapy if doses >300 mcg/hr are required. Replace patch every 72 hr and apply the new patch to a different site; avoid using the same area of skin for a few days. Refer to opioid conversion table in prescribing information Elderly: Dose reduction may be needed.

Child Dose

Renal Dose

Administration

Contra Indications

Hypersensitivity.

Precautions

Myasthaenia gravis. Head injury; increased intracranial pressure; intracranial lesions; renal or hepatic impairment; neonates; opioid-nontolerant patients. Increased risk of respiratory depression in elderly, debilitated patients, patient with hypoxia or hypercapnia. Hypothyroidism, prostatic hyperplasia, inflammatory bowel disorders, bradycardia or bradyarrhythmias. Rapid IV infusion may cause skeletal muscle and chest wall rigidity, impaired ventilation or respiratory distress/arrest. Prolonged use may cause tolerance, psychological and physical dependence. Abrupt withdrawal after prolonged admin may lead to withdrawal symptoms. Lactation. Pregnancy (avoid high doses or prolonged usage). Lactation: Drug distributed in breast milk; breastfeeding not recommended

Pregnancy-Lactation

Pregnancy Prolonged use of opioid analgesics during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth; observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly; opioids cross placenta and may produce respiratory depression and psycho-physiologic effects in neonates; an opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate; opioid sulfate is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate; opioid analgesics can prolong labor through actions which temporarily reduce strength, duration, and frequency of uterine contractions Fertility Due to effects of androgen deficiency, chronic use of opioids may cause reduced fertility in females and males of reproductive potential; it is not known whether effects on fertility are reversible Lactation Opioid is secreted into human milk; in women with normal opioid metabolism (normal CYP2D6 activity), the amount of opioid secreted into human milk is low and dose-dependent; some women are ultra-rapid metabolizers of opioid; these women achieve higher-than-expected serum levels of opioid's active metabolite, opioid, leading to higher-than-expected levels of opioid in breast milk and potentially dangerously high serum opioid levels in their breastfed infants that can potentially lead to serious adverse reactions, including death, in nursing infants Developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from therapy or from underlying maternal condition

Interactions

Concomitant use w/ CYP3A4 inhibitors (e.g. erythromycin, clarithromycin, troleandomycin, azole antifungals, ritonavir, amiodarone, nefazodone, aprepitant, diltiazem and verapamil) increases serum levels of fentanyl and may potentiate fatal resp depression. Increased risk of life-threatening serotonin syndrome w/ SSRIs, SNRIs and MAOIs. May reduce serum levels w/ rifamycin derivatives. Enhanced depressant effect w/ general anaesth, tranquilisers, barbiturates and narcotics. May increase excretion w/ ammonium Cl. May increase hypotensive effect w/ phenothiazines. May reduce efficacy of pegvisomant.

Side Effects

Side effects of Fentanyl : Reduce pulmonary compliance and/or apnoea, bronchoconstriction, laryngospasm; nausea, vomiting; bradycardia, oedema, CNS depression, confusion, dizziness, drowsiness, headache, sedation, hypotension, peripheral vasodilation, increased intracranial pressure, itching, rash, erythema, papules, pruritus, exfoliative dermatitis, pustules, macular rash; gum bleeding and irritation, taste perversion, dental caries, tooth loss, gum line erosion; throat irritation, nasal ulcers, epistaxis, rhinorrhoea; coughing; urinary retention. High IV dose may cause chest wall rigidity. Transdermal: Rash, erythema and itching. Potentially Fatal: Respiratory depression, trunk rigidity, laryngospasm, bronchoconstriction.

Mode of Action

Fentanyl is a potent opioid analgesic that increases pain threshold, alters pain reception and inhibits ascending pain pathways by binding to stereospecific receptors w/in the CNS.