Reduction in ATP production impairs the cells ability to extract calcium from the muscle cell. The ion imbalance causes calcium-dependent enzymes to activate which break down muscle proteins even further. A high concentration of calcium activates muscle cells, causing the muscle to contract while inhibiting its ability to relax. The increase of sustained muscle contraction leads to oxygen and ATP depletion with prolonged exposure to calcium. The muscle cell membrane pump may become damaged allowing free form myoglobin to leak into the bloodstream. Physiology
Rhabdomyolysis causes the myosin and actin to degenerate into smaller proteins that travel into the circulatory system. The body reacts by increasing intracellular swelling to the injured tissue to send repair cells to the area. This allows creatine kinase and myoglobin to be flushed from the tissue where it travels in the blood until reaching the kidneys. In addition to the proteins released, large quantities of ions such as intracellular potassium, sodium, and chloride find their way into the circulatory system. Intracellular potassium ion has deleterious effects on the hearts ability to generate action potentials leading to cardiac arrhythmias. Consequently, this can affect peripheral and central perfusion which in turn can affect all major organ systems in the body.When the protein reaches the kidneys it causes a strain on the anatomical structures reducing its effectiveness as a filter for the body. The protein acts as a dam as it forms into tight aggregates when it enters the renal tubules.
Retapamulin is a topical antibiotic developed by GlaxoSmithKline. It is the first drug in the new class of pleuromutilin antibiotics to be approved for human use. It is marketed as an ointment under the brand names Altabax and Altargo. Retapamulin was approved by the United States Food and Drug Administration in April 2007 for the treatment of bacterial skin infections such as impetigo. In May 2007, retapamulin received approval in the EU from the European Medicines Agency for the same indication. Clinical trials have demonstrated its efficacy against certain Gram-positive bacteria including MRSA. Indications
Retapamulin is indicated for the topical treatment of impetigo due to Staphylococcus aureus (methicillin-susceptible only) or Streptococcus pyogenes. Pharmacology
Mechanism of action
Retapamulin is an antibacterial agent, specifically a protein synthesis inhibitor. The medication selectively inhibits bacterial protein synthesis by interacting at a site on the 50S subunit of the bacterial ribosome through an interaction that differs from other antibiotics. Pharmacokinetics
Systemic exposure following topical application through intact skin is low. Contraindications
None yet reported. Adverse reactions
The most common reported adverse reaction was irritation at the application site. == References ==