•  Introduction.
•  Symptoms.
•  Infection.
•  complications.
•  Treatment and drugs.
•  Prevention.

 

 

Introduction:-

• Shingles is a viral infection that causes a painful rash on one side of the body. Often appears as a band of blisters that wraps between 2-3 weeks.
• Shingles is caused by the varicella-zoster virus (the same virus that causes chickenpox). After you've had chickenpox, the virus lies inactive in nerve tissue near your spinal cord and brain. Years later, the virus may reactivate as shingles.
• Causes of reactivation are unknown but mostly due to decreased immunity (more occurrence>50 years) and stress. 
• While it isn't a life-threatening condition, shingles can be very painful.

 

Symptoms:-

 

• Pain, burning, numbness or tingling.
• A red rash that begins a few days after the pain.
• Fluid-filled blisters that break open and crust over.
• Itching.

• Fever and chills.
• General achiness.
• Headache.
• Fatigue.

• The pain and rash occur near your eyes. If left untreated, this infection can lead to permanent eye damage.
• You or someone in your family has a weakened immune system (due to cancer, medications or chronic illness).
• The rash is widespread and painful.

• You can't catch shingles from someone else who has shingles. But a person with a shingles rash can spread chickenpox to another person who hasn't had chickenpox and who hasn't gotten the chickenpox vaccine. 
• If you have shingles, you are contagious especially the open sores of the shingles rash so avoid direct contact with people (especially newborns, pregnant women, any one has a weak immune system) until shingles blisters scab over. 
• Having had chickenpox can develop shingles.

 

Complications:- 

• Most people who get shingles will get better and will not get it again.

• Complications from shingles can range from a mild to severe, ranging from minor skin infections to post herpetic neuralgia (damaged nerve fibers with exaggerated pain).
• Other problems may be Vision loss, Encephalitis, an inflammation of the brain, Hearing or balance problems, Facial paralysis.
• If shingles blisters aren't properly treated, bacterial skin infections may develop.

• An episode of shingles usually heals on its own within a few weeks, but prompt treatment can ease pain, speed healing and reduce your risk of complications.
• There is no cure for shingles, but treatment may help you get well sooner and prevent other problems.

• Acyclovir (Zovirax), Valacyclovir (Valtrex), Famciclovir (Famvir).
• Drugs for the pain such as: Narcotics (e.g. oxycodone).
• Tricyclic antidepressants, such as amitriptyline
• Anticonvulsants, such as gabapentin (Neurontin).
• Numbing agents, such as lidocaine, delivered via a cream, gel, spray or skin patch.

• Anti-itch cream or calamine lotion.
• Oral antihistamines, such as diphenhydramine (Benadryl, others).

Prevention:-

 

• Two vaccines may help prevent shingles :  the chickenpox (varicella) vaccine and the shingles (varicella-zoster) vaccine.

• Varicella-zoster is part of a group of viruses called herpes viruses, which includes the viruses that cause cold sores and genital herpes. Because of this, shingles is also known as herpes zoster. But the virus that causes chickenpox and shingles is not the same virus responsible for cold sores or genital herpes, a sexually transmitted disease.

- Prepared by: Dr. Mustafa Abdel Tawab (pharmacist). - Resources:  -  mayoclinic.com  -  webmd.com.   -  Wikipedia.com. - Copyrights: All rights are reserved for pharmacist development group 2009 - 2011.

•  Quinolones general information.
•  Fluroquinolones, action, side actions and interactions.
•  Fluroquinolones group members in details.
•  Fluroquinolones in the clinical use.
•  Practical notes.
•  Rapid review.
•  Test yourself.

Slides titles :-

Drug name	# Acyclovir.
Brand name	# Zovirax.
Class of drug	# Antiviral agent.
Indications	# Herpes simplex (HSV-1 and HSV-2) infections and immune-compromised host. # Genital herpes infections. # Herpes simplex encephalitis. # Herpes zoster infections. # Chickenpox infections.
Mechanism of action	# Nucleotide analog; inhibits viral replication by termination of viral DNA chain and inhibition and inactivation of viral DNA polymerase.
route / Dosage form	# Route : Oral, IV, Topical. # Dosage form : Cap 200; Tab 400, 800 mg; Inj 500 mg, 1 g; Inj 50 mg/mL; Oint 5%; Susp 40 mg/mL
Dose	# Herpes simplex (HSV-1 and HSV-2) infections (immunocompromised host) * Adults, children >12 years: IV 5 mg/kg (infuse at constant rate over 1 hour), q8h for 7 days. * Children <12 years: IV 250 mg/m2 (infuse at constant rate for 1 hour), q8h. # Genital herpes * Adults, children >12 years: PO 200 mg q4h, five doses/day; 10 days for initial therapy. Dose for 5 days for intermittent recurrent disease. Administer up to 12 months for chronic disease (suppressive therapy). * Children <12 years: IV 250 mg/m2, t.i.d. for 10 days. # Herpes simplex encephalitis * Adults, children >12 years: IV 10 mg/kg (infuse at constant rate over 1 hour), q8h for 10 days. * Children, 6 months to 12 years: IV 500 mg/m2 (infuse at constant rate over 1 hour), q8h for 10 days. # Herpes zoster * Adults, children >12 years: PO 80 mg, q4h, five doses/day, 7–10 days. * Children <12 years: PO 250–600 mg/m2, 4–5 times/day, 7–10 days. # Chickenpox * Adults, children >40 kg: PO 800 mg, q.i.d. 5 days. * Children >2 years: PO 20 mg/kg q.i.d. (maximum 800 mg), 5 days.
Pregnancy / Lactation	# Pregnancy: Category C. # Lactation: Appears in breast milk.
Adverse reactions	# Common: headache, phlebitis (IV only). # Serious: seizures, renal failure, anaphylaxis, encephalopathy (confusion, hallucinations), coma, leukopenia, renal crystalline precipitant, elevated liver enzymes, Stevens–Johnson syndrome, urticaria.
Important interactions	# Drugs that increase effects/toxicity of acyclovir: MAO inhibitors, probenecid, ziduvine, CNS depressants. # Drugs that decrease effects/toxicity of acyclovir: β blockers, guanethidine.
Contraindications / precautions	# Use with caution in patients with the following conditions: kidney disease, neurologic disease. # Beware of renal dysfunction especially if patient is taking other nephrotoxic drugs. # Women with genital herpes should have annual Pap smears. # Rapid bolus administration may cause crystalline precipitation in renal tubules and renal insufficiency. # Patients receiving acyclovir IV must remain well hydrated during treatment and for 24 hours after treatment. # Cases of thrombotic thrombocytopenic purpura/hemolytic uremia syndrome have been reported with high-dose acyclovir in immunocompromised patients.
Other notes	# Kidney disease: dose should be adjusted according to creatinine clearance. # Pediatric: Safety has not been established in children <2 years old.
Practical notes	# Drink 2–3 L of fluid per day. This is particularly important following IV infusion. # Avoid sexual intercourse when lesions are present; otherwise use condoms. # Avoid contact of the drug with or around the eyes. # Resume treatment at first indication of recurrence of infection. # Use a finger cot or latex glove when applying acyclovir ointment. The ointment might cause transient burning or stinging.
Trade names	# Egypt :- Zovirax, Acyclovir, Virustat, Novirus, Lovir, Cycloviral. # KSA :- Zovirax, Virustat, Acyclovir, Acivir, Clovir, Custiviral, Deforax, Herpavir, Imavir, Lovrak, Medvirox, Noviral, Novirax, ,

- Prepared by: Dr. Mohamed Abdel Rahman (pharmacist). - Resources:  - Handbook of clinical drug data, 10th edition. - Clinician's handbook of prescription drugs . - Physicians' Drug manual 2005 edition .  -  Master of Egyptian drugs.  -  Master of Saudi drugs. - Copyrights: All rights are reserved for pharmacist development group 2009 - 2011.