Acyclovir for the Treatment of the Shingles.

Acyclovir for the Treatment of the Shingles.

What is a Shingles?

Shingles is a condition that are causes to a painful skin rash with a blisters. It is appears along to a nerve due to the reactivation of the varicella zoster infection.

The varicella zoster virus (V Z V) causes chickenpox, which are usually affects susceptible children. After in the primary infection, in the V Z V lays dormant in the dorsal-root ganglia, in the parts of the nervous system from where sensory nerves arise. When the person’s immune in a system is a compromised or a during old age, in the V Z V can get a reactivated and cause herpes zoster, commonly known as a shingles.

The rash of the shingles comprises of the blisters and occurs in a single stripe either on the left or a right of the body or a face, along in the course of a nerve. There may be a tingling or a local pain in the area a day or a two before in the appearance of the rash. The healing period for in the rash is two to four weeks; except when a ongoing nerve pain (prosthetic neuralgia) are develops, which pushes in the healing to the months or a years. The rash can be a widespread if you have to a poor immune function. Vision loss may be occur if the eyes get a affected.

What is a Acyclovir?

Acyclovir, to a nucleoside analogue, is the first successful antiviral medication, and the works well against most species in the herpes-virus in a  family. It is a effective against viral infections that are include herpes simplex virus (H S V 1 and H S V 2) infections, chickenpox, and the shingles.

Acyclovir’s are discovery was a announced in a 1977, though it was a approved by the US Food and Drug Administration (FDA) and the available for a commercial use only in a 1982. Acyclovir is a included in the World Health Organization (WHO) “List of  the Essential medicines”, which are includes drugs that are "in the safest and most effective medicines needed in a health system".

How is a Acyclovir Administered?

Acyclovir can be taken a orally as a capsule, oral suspension, or a tablet, applied as a cream, or can be a injected.

Oral treatment of the shingles:

Adults and children 12 years of the age and older are prescribed 800 mg five times a day for a seven to the ten days.

Children less than a 12 years of the age are prescribed dosages based on their age or a body weight.

Limitations in a giving the drug orally are its low bio-availability (in the amount of the drug that is a absorbed and reaches in the circulation) and its frequent dosing (five times daily).

Treatment of the shingles via injection:

The inject-able dose for a children as well as a adults must be a determined by the doctor who decides it is based on the body weight of the patient. The drug is a injected into a vein over at the least a one-hour period. It is a repeated every eight hours for a five to ten days.

The intravenous administration is a considered generally only in a patients who are severely compromised or unable to take in the medications orally.

The usual dose for a adults and children 12 years of the age and older is 5 to 10 mg of the  acyclovir per kg of the body weight.

The usual dose for a children less than 12 years of the  age is 10 mg to 20 mg of the acyclovir per kg of  the body weight.

What is the Mechanism of Action of the Acyclovir?

Acyclovir acts on the DNA of the susceptible viruses, which is a critical for in their survival. It is a converted to its mono-phosphate form by a viral enzyme, and is a later converted into it is a tree phosphate form, acyclovir tree phosphate (A C V-T P) by a cellular enzymes. The phosphate form then gets a incorporated into the DNA and deactivates in the DNA polymer enzyme that is a required for a viral DNA synthesis. In a doing so, it terminates the growing viral DNA chain and prevents further DNA production.

Points to Note:

Acyclovir is a poorly water-soluble and is a slowly and poorly absorbed from the digestive tract into the circulation resulting in a very low oral bio-availability of  the 15–30%. This bio-availability further decreases with a increasing dose. Therefore, intravenous administration is a preferred when high concentrations are needed

The drug is a highly distributed into a tissues and body fluids. Protein binding is a relatively low at the 9 to 33%.

The drug is a mostly eliminated unchanged out of the body through in the kidneys; in the rate at which in the drug is a eliminated depends on the age of the patient.

Caution is a advised when giving the drug to those with a poor liver or a kidney function.

Acyclovir-is considered as a Category B drug for a pregnant women and is a considered as a relatively safe.

Acyclovir are appears to be a safe during breastfeeding.

When simultaneously given with a another drug providence, in the latter can reduce in the excretion of the acyclovir in the urine, thereby increasing its blood level.

What are the Side Effects of the Acyclovir?

Nausea and diarrhea

Headache, lightheartedness, malaise

Abdominal pain

Reactions at the site of the injection during IV use

Potentially serious side effects are include kidney problems and low platelet levels in a blood.

With in the topical form, one can be suffer from a mild pain, burning and stinging locally.

References:

Acosta E P, Balfour H H. Acyclovir for a Treatment of  the Prosthetic Neuralgia: Efficacy and Pharmaceutics. Antimicrobial Agents and Chemotherapy. 2001;45(10):2771-2774.

Sampathkumar P, D rage LA, Martin DP. Herpes Zoster (Shingles) and Prosthetic Neuralgia. Mayo Clinic Proceedings. 2009;84(3):274-280.

DE Bony F, Tod M, Biddable R, On NT, Poser J, Rolan P. Multiple Interactions of the Cimetidine and the  Providence with a Valaciclovir and It is a Metabolite Acyclovir. Antimicrobial Agents and the Chemotherapy. 2002;46(2):458-463.

Gnann J W Jr, Barton NH, Whitley R J. Acyclovir: mechanism of action, pharmacokinetics, safety and clinical applications. Pharmacotherapy. 1983 Sep-Oct;3(5):275-83.

Acyclovir -

(http://www.antimicrobe.org/new/drugpopup/Acyclovir.pdf)

Acyclovir Oral Route Intravenous Route -

(http://www.mayoclinic.org/drugs-supplements/acyclovir-oral-route-intravenous-route/description/drag-20068393)

What is a Acyclovir? -

(https://en.wikipedia.org/wiki/Acyclovir)

Why is this medication  are prescribed? -

(https://medlineplus.gov/druginfo/meds/a681045.html)

Prescribing Information -

(https://www.accessdata.fda.gov/drug-sat FDA_docs/label/2005/018828s030,020089s019,019909s020lbl.pdf).