Prednisolone acts by controlling the rate of synthesis of proteins. Corticosteroids interact with specific receptor – proteins in the cytoplasm sensitive cells to form, a steroid receptor complex. This complex moves into the nucleus, where it binds to chromatin to regulate the expression of corticosteroid responsive genes. As a result they change the levels and array of proteins synthesized by the various target tissues, as a consequence the time required for changes in gene expression and protein synthesis, most effects of corticosteroids are not immediate, but become apparent after several hours.
Corticosteroids predominantly act to increase expression of target genes. Here are well-documented, examples where gluco-corticosteroids decrease transcription of target genes. In contrast to their genomic effects, recent studies have raised the possibility ha some actions of corticosteroids are immediate and mediate by membrane-bound receptors.
Prednisolone is readily absorbed from the gastro-intestinal tract and already exists in a metabolically active form. Peak plasma concentration of prednisolone are obtained 1 or 2 hours after administration by mouth and it has a usual plasma half-life of 2 to 4 hours. Prednisolone is extensively bound o plasma proteins. Prednisolone is excreted in the urine as free and conjugate metabolites. Prednisolone crosses the placenta and small amounts are excreted in breast milk. Prednisolone has a biological half-life lasting several hours.
Suppression of inflammatory disorders and allergic disorders, inflammatory bowel disease, asthma, rheumatic disease.
Systemic infection (unless specific antimicrobial therapy given). Avoid live virus vaccines in those receiving immunosuppressive doses (serum antibody response diminished)
- Gastro-intestinal effects include dyspepsia, peptic ulceration, abdominal dissension
- Musculoskeletal effects include osteoporosis, vertebral, long bone fractures, proximal myopathy
- Endocrine effects include adrenal suppression, menstrual irregularities and syndrome
- Neuropsychiatric effects include euphoria psychological dependence, depression, insomnia
- Ophthalmic effects include glaucoma, papilloedema, posterior sub-capsular cataracts.
- Other side effects include impaired healing, skin atrophy rupture
Precautions and warnings
- Pregnancy and breast feeding
- Frequent monitoring required in those with history of tuberculosis, hypertension, recent myocardial infarction, congestive heart failure, liver failure, renal impairment, diabetes mellitus, epilepsy
- Minimized by using lowest effective dose for minimum period possible
Recommended dosage and dosage schedule
By mouth initially up to 10-20 mg daily, preferably taken in the morning after breakfast. It can often be reduced within a few days but may need to be continued for several weeks or months. Maintenance, usually range from 1.5 to 2.5mg daily or as directed by the physician
Signs and symptoms of over dosage
Symptoms: skin rashes, urticarial and ache. Overdose of prednisolone may produce toxic symptoms called Cushingoid symptoms (typical of hyperactivity of the Adrenal cortex). Moon face sometimes with Hirustism, buffalo hump, increased bruising, stoniae, acne. Overdose of prednisolone may produce hypersensitivity reactions
Treatment: over dosage of prednisolone should be treated symptomatically, where possible the dosage should be progressively reduced or the drug is slowly withdrawn