Tuesday, April 11, 2006

Day 12

I talked to Dr. Durkes about Mickey's rear-end weakness worsening again, he thinks Mick might have jerked or bumped his neck and that caused some inflammation to come back.

We are going to put him on prednisone for two weeks to see if that helps, he'll only be getting 20 mg a day, so side effects should be minimal.

Here is some information on Prednisone:

Background
Prednisone is a synthetic corticosteroid used for many conditions in both human and veterinary medicine. Its anti-inflammatory activity is approximately four times that of hydrocortisone. Corticosteroids are extremely effective anti-inflammatory drugs because they affect the inflammatory process at so many different levels. Prednisone is rapidly converted to prednisolone in the liver and in most instances, these drugs are considered to be roughly equivalent. Corticosteroids have strong beneficial effects but a definite potential to cause negative side effects if abused. Prednisone may be given by injection, orally or topically.

Side Effects
• Systemic side effects to corticosteroids are generally dependent on dose and duration of treatment. Short-term use of prednisone is unlikely to cause adverse effects. Adverse effects are more common in animals on immunosuppressive doses.
• Side effects seen in dogs include polyuria, polydipsia, polyphagia, poor haircoat, GI disturbance, diarrhea, vomiting, weight gain, GI ulceration, pancreatitis, lipidemia, elevated liver enzymes, diabetes mellitus, muscle wasting, and possible behavioral changes.
• Polyuria, polydipsia, polyphagia may be seen in dogs even on short-term therapy.
• Although cats are less likely to develop side effects than dogs, occasionally polyuria, polydipsia, polyphagia, weight gain, GI disturbances and behavioral changes occur.
• Corticosteroids can cause or worsen gastric ulcers.


Precautions
• Chronic or inappropriate use of corticosteroids, including prednisone, can cause life threatening hormonal and metabolic changes.
• Adverse effects due to corticosteroid treatment usually occur with long-term administration of the drug, especially when high doses are used. Alternate day therapy with short acting preparations is preferred. Animals who have received long-term therapy should be withdrawn slowly by tapering the dosage and prolonging the interval between doses.

• Corticosteroids suppress immune response. Animals receiving systemic corticosteroids may be more susceptible to bacterial or viral infections. Systemic corticosteroids can mask signs of infection, such as an elevated temperature.
• Systemic corticosteroids are contraindicated in patients with systemic fungal infections. (The treatment of Addison's disease may be considered an exception.)
• Prednisone must be converted to prednisolone in the liver. Animals in hepatic failure should receive prednisolone rather than prednisone.
• Corticosteroids should be avoided or used very carefully in young animals both because of immune suppression and the risk of GI ulcers.
• Corticosteroids should be avoided during pregnancy and lactation unless the benefits outweigh the risks. Large doses in early pregnancy may be teratogenic. Corticosteroids can induce labor in cattle and have been used to terminate pregnancy in bitches.


Drug Interactions
• When amphotericin B or diuretics such as furosemide are given with corticosteroids, there is an increased risk of electrolyte imbalances due to calcium and potassium losses.
• Digitalis and potassium levels should be closely monitored in animals taking prednisone.
• Corticosteroids may increase insulin requirements. Estrogen may potentiate the effects of corticosteroids.
• Drugs that may cause drug interactions with prednisone include salicylate, phenytoin, phenobarbital, rifampin, cyclosporin, erythromycin, mitotane and anticholinesterase drugs such as neostigmine and pyridostigmine.
• The immune response to vaccination may be reduced when corticosteroids are given at the same time.
• The risk of GI ulcers may be increased if corticosteroids and other drugs prone to causing ulcers such as nonsteroidal anti-inflammatory drugs are given at the same time.

Overdose
• Short-term administration of even large doses is unlikely to cause serious harmful systemic effects due to adrenal suppression. Problems associated with long-term administration of prednisone relate to suppression of normal adrenal function, iatrogenic Cushing's disease and metabolic crisis due to abrupt withdrawal.

Drug information compliments of http://www.wedgewoodpharmacy.com/monographs/prednisone.asp

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