An initial dosage of 0.4 to 0.5 mg/kg/dose IV every 6 hours (infused over 3 hours) was given to 2 term neonates with pulmonary hypertension secondary to congenital diaphragmatic hernia.
3. Downsides
The pharmacokinetics of sildenafil are highly variable in neonates; careful dose titration and monitoring is recommended. Prior to the release of pediatric pulmonary hypertension guidelines, the generally accepted dose of sildenafil was 0.5 to 2 mg/kg/dose every 6 to 8 hours, with doses ranging up to 3 mg/kg/dose every 6 hours ; however, guidelines recommend more conservative dosing based on a greater risk of mortality in pediatric patients (age 1 to 17 years) treated with high dose sildenafil monotherapy, as seen in the STARTS-2 trial. Relevance of this data to the neonatal population is unclear. 0.4 mg/kg IV loading dose over 3 hours followed by a continuous infusion of 0.067 mg/kg/hour (1.6 mg/kg/day); this dose has been proposed based on the results of an open-label, dose-escalation study in 36 term neonates. Very limited data are available; intermittent IV infusions have been used when oral intake was not possible in 3 neonates. The dose was gradually titrated up to 2 mg/kg/dose IV based on clinical response.
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For doses less than 1.5 mg/kg/dose IV, the infusion time was gradually decreased to over 1 hour (weaned by 1 hour every 36 to 48 hours). The third neonate (gestational age 25 weeks, postnatal age 18.6 weeks) was receiving oral sildenafil 1.67 mg/kg/dose PO every 6 hours and was converted to sildenafil 1.25 mg/kg/dose IV every 6 hours when she became "nothing-by-mouth" (NPO) status. All 3 neonates were also receiving inhaled nitric oxide at the time of sildenafil initiation.
Notes et références
If you do experience any of the above severe side effects, you should seek urgent medical attention. Handled correctly, sildenafil citrate is a generally safe and effective way to treat erectile dysfunction. But you should always read the Patient Information Leaflet before taking it. To find out more, book a consultation with one of our clinicians. Phosphodiesterase Inhibitors for EDPhosphodiesterase Inhibitors for PAH May be administered without regard to meals.
How does sildenafil work (mechanism of action)?
Shake well for at least 10 seconds prior to each administration.Measure dose with an oral dosing syringe or calibrated measuring device.Concentration of the suspension is 10 mg/mL. Oral suspension (e.g., Liqrev)Storage: Store at room temperature of 20 to 25 degrees C (68 to 77 degrees F). Discard any unused portion after 90 days of opening the bottle.Powder for oral suspension (e.g., Revatio or generic equivalents)):Do not mix with any other medication or additional flavoring agent.Prior to reconstitution, tap the bottle to loosen the powder.Reconstitute with a total of 90 mL of water added in 2 portions. Initially, add 60 mL of water to the bottle and shake vigorously for at least 30 seconds. Add the remaining 30 mL of water and shake vigorously for at least 30 seconds.Remove the cap and press the adaptor for the oral syringe into the neck of the bottle; replace cap.Write an expiration date of 60 days from the date of reconstitution on the bottle label.Storage: Store below 30 degrees C (86 degrees F) or in refrigerator at 2 to 8 degrees C (36 to 46 degrees F).
Before taking sildenafil,
Discard any unused portion after 60 days. Extemporaneous 2.5 mg/mL sildenafil oral suspension:NOTE: Extemporaneously prepared sildenafil oral suspension is not approved by the FDA; an FDA-approved powder for oral suspension is now commercially available.With a mortar and pestle, grind thirty 25-mg sildenafil citrate tablets to a fine powder.In a separate container, mix 1 of the following: 1) 150 mL of Ora-Sweet with 150 mL of Ora-Plus; or 2) 150 mL of Simple Syrup, NF with 150 mL of methylcellulose 1%.Add a small amount of the mixture to the fine powder and mix into a uniform paste. Add geometric amounts of the vehicle to the almost desired volume while mixing. Transfer to a graduated cylinder and adjust to volume while mixing.Place in amber plastic bottles. Shake well before each use.Storage: This suspension is stable for 91 days when stored at 4 and 25 degrees C. The duration of treatment ranged from 6 to 51 days, and respiratory support was able to be decreased over time in all patents.
Ways to Maximize the Effectiveness of Sildenafil
Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit. Sildenafil injection is available as a ready to use solution; further dilution is not required.Administer as an IV bolus injection. May decrease the dose to 25 mg or increase the dose to 100 mg PO as needed approximately 1 hour before sexual activity. The dose may be taken from 30 minutes to 4 hours before sexual activity. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions.
How is sildenafil supplied (dosage forms)?
25 mg PO as needed approximately 1 hour before anticipated sexual activity. May increase the dose up to 100 mg PO as needed approximately 1 hour before sexual activity. Dose may be titrated as needed based on symptoms and tolerability to a maximum of 80 mg PO 3 times daily. Although dose-response improvement in exercise ability was not observed in short-term clinical trials in adults with pulmonary hypertension, the delay in clinical worsening with long-term use of sildenafil in a clinical trial supports dosing up to a maximum of 80 mg PO 3 times daily. A maximum dose in pediatric patients has not been identified.
Does sildenafil interact with foods or drinks?
Based on experience in adults, the dose may be titrated as needed to a maximum of 40 mg PO 3 times daily based on symptoms and tolerability. Avoid higher dosing due to a greater sildenafil 25mg tablets risk of mortality in pediatric patients (age 1 to 17 years) treated with high dose sildenafil monotherapy. 0.5 to 1 mg/kg/dose PO every 8 hours. Prior to the release of pediatric pulmonary hypertension guidelines, the generally accepted dose of sildenafil was 0.5 to 2 mg/kg/dose every 6 to 8 hours, with some regimens, particularly those described in earlier reports, administering doses every 4 hours; however, guidelines recommend more conservative dosing based on a greater risk of mortality in pediatric patients (age 1 to 17 years) treated with high dose sildenafil monotherapy, as seen in the STARTS-2 trial. Relevance of this data to the infant population is unclear. Hepatic dosing adjustments for adults with erectile dysfunction:Consider a starting dose of 25 mg in adults with any degree of hepatic impairment.Hepatic dosing adjustments for patients with pulmonary hypertension:No adjustment needed for adults with mild to moderate hepatic impairment (Child Pugh class A or B). The effect of severe hepatic impairment (Child Pugh class C) has not been studied.
| Condition | Temperature Range | Light Exposure | Additional Notes |
|---|---|---|---|
| General storage | 20-25°C (68-77°F) | Keep in original container | Avoid moisture and heat |
| Refrigeration | Not required | No | If needed, store in fridge |
| Avoid exposure | Humidity, direct sunlight | Yes | To preserve potency |
Specific guidelines for pediatric patients are not available.
- Sildenafil citrate was approved by the FDA in 1998.
- Its discovery revolutionized the treatment of erectile dysfunction.
- The medication requires sexual stimulation to be effective.
- It is not an aphrodisiac; it facilitates natural response.
- Overdose symptoms may include severe hypotension.
- Recreational use of sildenafil without prescription is risky.
- Combining with alcohol can increase side effects.
- It should be stored at room temperature away from moisture.
Renal dosing adjustments for adults with erectile dysfunction:CrCl 30 mL/minute or greater: No dosage adjustment is needed.CrCl less than 30 mL/minute: Reducing starting dose to 25 mg PO.Renal dosing adjustments for patients with pulmonary hypertension:No adjustment needed for adults with renal impairment, including adults with severe renal impairment (CrCl less than 30 mL/minute).
| Indication | Patient Group | Dosage Recommendation | Additional Notes |
|---|---|---|---|
| Erectile Dysfunction | Men aged 18-65 | 50 mg30-1 hour before activity | Adjust based on efficacy and tolerability |
| Pulmonary Hypertension | Adults with PAH | 20 mg three times daily | Extended release available |
| Raynaud's Phenomenon | People with secondary Raynaud's | Off-label use, consult physician | Limited clinical evidence |
Specific guidelines for pediatric patients are not available.Intermittent hemodialysisFollow recommendations for patients with CrCl less than 30 mL/minute. A decreased pressor effect of phenylephrine might occur. Monitor for proper blood pressure when these drugs are used together.
- Sildenafil citrate can also treat pulmonary arterial hypertension.
- It enhances exercise capacity in patients with this condition.
- The drug’s effects usually last 4-6 hours.
- Taking it with a high-fat meal can delay absorption.
- Sildenafil should not be used with nitrate medications.
- Serious side effects include vision changes and priapism.
- It is contraindicated in individuals with certain heart conditions.
- Patients should inform their doctor about all medications.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Minor) The therapeutic effect of phenylephrine injection may be decreased in patients receiving phosphodiesterase inhibitors.
- Sildenafil works by inhibiting phosphodiesterase type 5 enzyme.
- This inhibition increases cGMP levels in the body.
- Elevated cGMP leads to smooth muscle relaxation.
- It promotes vasodilation in the corpus cavernosum.
- This process facilitates an erection during sexual activity.
- The drug’s pharmacokinetics allow for rapid absorption.
- Food intake can influence absorption rate.
- It is effective in men of various ages.
Acetaminophen; Dextromethorphan; Phenylephrine: (Minor) The therapeutic effect of phenylephrine injection may be decreased in patients receiving phosphodiesterase inhibitors.
How should this medicine be used?
0.22 to 0.5 mg/kg/dose PO as a single dose 1 hour prior to discontinuing iNO or 4 times daily. None of the 15 patients receiving a single sildenafil dose of 0.3 to 0.5 mg/kg/dose PO 1 hour prior to discontinuation of iNO experienced rebound pulmonary hypertension compared to 10 of 14 patients receiving placebo. In 7 patients receiving sildenafil 0.22 to 0.47 mg/kg/dose PO 4 times daily, mean iNO dose was significantly reduced compared to baseline within 24 hours of sildenafil initiation (12.2 vs. 29.8 ppm, p = 0.024). Guidelines recommend sildenafil use to prevent rebound pulmonary hypertension and facilitate iNO weaning in patients with evidence of increased pulmonary artery pressure upon iNO withdrawal; however, they do not provide specific dosing.
Hazard Classifications
Recommended maintenance dosing for pulmonary hypertension is 0.5 to 1 mg/kg/dose PO 3 times daily in persons younger than 1 year, 10 mg PO 3 times daily in persons weighing 20 kg or less, and 20 mg PO 3 times daily in persons weighing more than 20 kg. A double-blind, placebo-controlled, crossover study evaluated sildenafil for symptomatic secondary Raynaud's phenomenon resistant to vasodilatory therapy. Patients (n = 18, 15 were female) were randomly assigned to receive placebo or sildenafil 50 mg PO twice daily for 4 weeks; a washout period of 1 week was used before crossover. The results showed that sildenafil significantly improved microcirculation and symptoms associated with Raynaud's. In patients with chronic digital ulcerations, sildenafil treatment resulted in healing of trophic lesions which sildenafil tables reappeared or progressed when sildenafil was stopped.
How should I store sildenafil?
Ulcerations did not heal while receiving placebo. Sildenafil therapy may be an alternative therapy in patients with Raynaud's resistant to vasodilatory therapy. 50 mg PO every 8 hours starting the day before ascent and continuing for 5 days after reaching the target altitude or until descent is initiated as an alternative to nifedipine. Prophylactic medications should only be considered for individuals with a prior history of high altitude pulmonary edema. Delay use in extremely premature infants until retinal vascularization is established. Acetaminophen; Guaifenesin; Phenylephrine: (Minor) The therapeutic effect of phenylephrine injection may be decreased in patients receiving phosphodiesterase inhibitors.
- Sildenafil citrate can be combined with lifestyle changes.
- Exercise and weight management improve erectile function.
- Quitting smoking enhances medication effectiveness.
- Reducing alcohol intake minimizes side effects.
- Psychological therapy may support ED treatment.
- Counseling can address underlying emotional issues.
- Regular medical check-ups are recommended.
- Patient education improves safe and effective use.