fentanyl injection

Fentanyl is a strong, synthetic (man-made) narcotic that is similar to morphine.

A 0.1 mg dose of fentanyl is approximately equal to 10 mg of morphine administered by intramuscular injection. Fentanyl stimulates receptors on nerves in the brain to increase the threshold of pain (the amount of stimulation it takes to feel pain) and reduce the perception of pain (the perceived importance of the pain).

Fentanyl is available in transdermal (for application to the skin), transmucosal (for application to mucus membranes), and parenteral (injectable) forms. Fentanyl was originally approved by the FDA for injection in 1968.

Fentanyl is a controlled substance and is habit forming. Mental and physical dependence can occur. Abruptly stopping the drug in patients who have been taking the drug for a long time can precipitate a withdrawal reaction. Symptoms of withdrawal include nausea, diarrhea, coughing, tearing, nasal discharge, profuse sweating, twitching muscles, and yawning.

Fentanyl can cause respiratory depression (decreased rate or depth of breathing), muscle rigidity, and reduced heart rate.

Additional side effects are:

• nausea,
• vomiting,
• constipation,
• drowsiness, and
• itching.

Other important side effects include:

• dry mouth,
• abdominal pain,
• loss of appetite,
• confusion,
• headache,
• dizziness,
• nervousness,
• hallucinations,
• anxiety,
• depression, and
• euphoria.

• Fentanyl injection can be injected into a muscle (intramuscular) or into veins (intravenous).
• The usual dose for surgical premedication in adults is 0.05 mg to 0.1 mg per dose given by intramuscular injection or by intravenous injection.
• For anesthesia, the dose is 0.5 to 20 mcg/kg per dose given intravenously.
• A maintenance intravenous infusion of 1-2 mcg/kg/hour also may be used.
• There are several recommended regimens for treating pain.
• Fentanyl also is used for patient-controlled anesthesia (PCA).

• The use of fentanyl with other central nervous system depressants can intensify the depressant effect of fentanyl on breathing, depress the brain, sedate, and lower blood pressure.
• Other drugs that should be used cautiously with fentanyl include antipsychotics, for example, thorazine, stelazine, and haloperidol (Haldol), anxiolytics, for example, diazepam (Valium), lorazepam (Ativan), and zolpidem (Ambien), certain antihistamines, for example, diphenhydramine (Benadryl) and hydroxyzine (Vistaril), barbiturates, for example, phenobarbital (Donnatal), tricyclic antidepressants, for example, amitriptyline (Elavil, Endep) and doxepin (Sinequan), alcohol, and skeletal muscle relaxants, for example, carisoprodol (Soma), cyclobenzaprine (Flexeril) and baclofen (Lioresal).
• The use of fentanyl with amiodarone (Cordarone) may result in a slow heart rate. Cimetidine (Tagamet) when used with fentanyl can cause confusion, disorientation, or seizures due to impairment in breathing and brain function.
• The monoamine oxidase inhibitor (MAOI) class of antidepressants, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), selegiline (Eldepryl), and procarbazine (Matulane) significantly increase the action of fentanyl resulting in more side effects. Fentanyl should not be used in patients taking MAOIs or within 14 days of stopping MAOIs.
• Combining fentanyl with drugs that reduce activity of liver enzymes that breakdown fentanyl, for example, ritonavir (Norvir), ketoconazole (Nizoral, Extina, Xolegel, Kuric), itraconazole (Sporanox), troleandomycin, clarithromycin (Biaxin, Biaxin XL), nelfinavir (Viracept), nefazadone, amiodarone, amprenavir (Agenerase), aprepitant, diltiazem (Cardizem, Dilacor, Tiazac), erythromycin, fluconazole (Diflucan), fosamprenavir, and verapamil (Calan, Verelan, Verelan PM, Isoptin, Isoptin SR, Covera-HS), may result in an increase in fentanyl blood levels, increasing or prolonging side effects of fentanyl.

• Fentanyl can cross the placenta and enter the fetus. Effects on the developing fetus are not known; however, fentanyl can slow breathing in newborn infants whose mothers were exposed to fentanyl. Routine use of fentanyl by pregnant women can lead to withdrawal reactions in the newborn. Thus, caution should be used if fentanyl is administered near the time of delivery.
• The effects of fentanyl on the infants of mothers who nurse is unknown. Since most drugs are concentrated in breast milk, it is advisable that women requiring fentanyl bottle-feed their infants.

What preparations of fentanyl are available?

• Injection Solution: 0.05 mg/ml

How should I keep fentanyl stored?

• Fentanyl injection should be stored at room temperature 20 C to 25 C (68 F to 77 F) and protect it from light.