Das pharmakologische Profil von Sildenafil zeigt neben der PDE5-Inhibition auch eine geringe Aktivität an der PDE6 in der Retina. Dies erklärt visuelle Nebenwirkungen wie Farbsehstörungen, die gelegentlich auftreten. Die orale Bioverfügbarkeit beträgt etwa 40 %, mit einer hohen Bindung an Plasmaproteine. Das Verteilungsvolumen ist groß, sodass die Substanz rasch in verschiedene Gewebe gelangt. Die Metabolisierung erfolgt hepatisch und produziert einen aktiven Metaboliten, der die pharmakologische Wirkung ergänzt. Nebenwirkungen sind dosisabhängig und umfassen Kopfschmerzen, Hautrötung und Dyspepsie. Bei Vergleichen innerhalb der Wirkstoffklasse wird viagra original regelmäßig als Beispiel für eine Substanz mit schneller, aber kurzzeitiger Wirkung aufgeführt.

Sadvtreatmentcentres.com2

If the client is on ANY of these drugs OR has any of the health conditions listed, consult a MD.
If there are concerns re: interactions with any drug not listed, consult a Pharmacist/HIV Expert. CONTRAINDICATED
Use with CAUTION
Antiarrhythmics ▪ Flecainide (Tambocor®) Antiarrhythmics ▪ Amiodarone (Cordarone®) Antibiotics ▪ Rifampin (Rifadin®, Rofact®) Antihistamines ▪ Astemizole (Hismanol®) Antibiotics ▪ Clarithromycin (Biaxin®) Ergot Derivatives ▪ Bellergal Spacetabs® Anticonvulsant ▪ Carbamazepine (Tegretol®) Antifungals ▪ Itraconazole (Sporanox®) GI Mortality Agents ▪ Cisapride (Propulsid®)3 Herbal Products ▪ St. John’s Wort (Hypericum perforatum) Calcium Channel Blockers ▪ Felodipine (Plendil/Renedil®) ▪ Nicardipine (Cardene®)▪ Nifedipine (Adalat®) Corticosteroids ▪ Dexamethasone (Decadron®) Immunosuppressants ▪ Cyclosporine (Neoral®, Sandimmune®) Inhaled Steroids ▪ Fluticasone (Flonase®, Advair®) PDE5 Inhibitors ▪ Sildenafil (Viagra®) ▪ Tadalafil (e.g., Cialis®)▪ Vardenafil (Levitra®) Oral/Patch Contraceptive ▪ Norethindrone Statins ▪ Atorvastatin (Lipitor®) or Rosuvastatin 1 History of hepatitis does not rule out HIV PEP. MD and/or HIV Expert consultation recommended. Possible contraindication in the event of acute symptomatic illness or severely elevated liver enzymes (> 5X normal). Dosage adjustments may be necessary. 2 Not all drugs within each drug class are contraindiated - only drugs listed above are contraindicated when co-administered with either Combivir® or Kaletra®.
3 Product no longer available in Canada, only available in the United States.
4 If it is suspected that the client is emotionally unstable and/or at risk of overdosing, it is recommended to use Combivir® alone.
If the client is on ANY of these drugs OR has any of the health conditions listed, consult a MD.
If there are concerns re: interactions with any drug not listed, consult a Pharmacist/HIV Expert. CONTRAINDICATED
Use with CAUTION
Health Abnromally low neutrophil count (< 0.75 x 109/L) ir® Conditions Abnormally low hemoglobin levels (< 75 g/L)
Pancreatitis (history OR risk factors) 5Kidney problems ▪ Trimethoprim-sulfamethoxazole (Septra®) b Precautions
▪ Amphotericin B▪ Fluconazole (Diflucan®) ▪ Stavudine (Zerit®)▪ Zalcitabine (Hivid®) ▪ Interferon alpha (Roferon®-A, Intron® A, 1 History of hepatitis does not rule out HIV PEP. MD and/or HIV Expert consultation recommended. Possible contraindication in the event of acute symptomatic illness or severely elevated liver enzymes (> 5X normal). Dosage adjustments may be necessary. 2 Not all drugs within each drug class are contraindiated - only drugs listed above are contraindicated when co-administered with either Combivir® or Kaletra®.
3 Product no longer available in Canada, only available in the United States.
4 If it is suspected that the client is emotionally unstable and/or at risk of overdosing, it is recommended to use Combivir® alone.
5 Increased concern in paediatric clients.
Non-essential medications, alternate therapy, vitamins and recreational drug use should be discontinued during the HIV PEP regimen (e.g., herbal mood enhancers/sleep aids such as 5-hydroxy-L-triptophan (5HTP or Tryptophan); multi-vitamins).
Kaletra® can decrease the effectiveness of long-term use birth control pills. Barrier form contraceptive (e.g., condom) should be used for 28 days + 2 months.
The use of Combivir® and Kaletra® during pregnancy has not been extensively studied. IF a woman is pregnant: HIV PEP drugs are potentially teratogenic in the 1st trimester (often avoided during this period).
Since Kaletra is a substrate and potent CYP3A4 inhibitor, caution should be used when co-administering Kaletra and CYP3A4 enzyme inducers, inhibitors, or substrates with narrow therapeutic indices. If in doubt, please consult with an HIV Expert or Pharmacist. STOP HIV PEP if: Grade 4 AE; Hemoglobin <80 g/L; Absolute Neutrophil < 0.5 x 109/L; Platelet Count <20,000 cells/µL; AST / ALT / ALP
/ Bilirubin > 5X upper limit of normal.

Source: http://sadvtreatmentcentres.com/files/contraindicationsquickreferencechart.pdf