Inorganic Pharmaceutical Chemistry Lecture Notes PDF

Lec. 5 Inorganic pharmaceutical chemistry NON-ESSENTIAL IONS Assistant lecturer: Shahbaa Shafeeq  NON-ESSENTIAL IONS: Fluoride: Fluoride are widely used today for their anticariogenic action (inhibition of dental cavity development), also required...

Lec. 5 Inorganic pharmaceutical chemistry NON-ESSENTIAL IONS Assistant lecturer: Shahbaa Shafeeq  NON-ESSENTIAL IONS: Fluoride: Fluoride are widely used today for their anticariogenic action (inhibition of dental cavity development), also required for bones and act as inhibitor of certain enzymes. About 95% of orally taken fluoride is absorbed. Many reports indicated that fluoride reduces the prevalence of osteoporosis. Visible aortic calcification were actually higher in low fluoride area because fluoride facilitate calcium deposition in hard tissues rather than soft tissues.  Bromide: Bromides were introduced into medicine in 1853 for their antiepileptic effect. Administration of small doses (0.5-2 gm) of bromide, (e.g., KBr) serves to cause depression to CNS, while large doses (4-8 gm) may depress all reflexes and cause narcotic type effect. Bromides usefulness in epilepsy depends on their ability to depress the motor areas of the brain, an effect brought about by large doses. Recently bromide as (sodium or potassium salt) is used only for grand mal seizures in children in whom other drugs prove unsuitable.  Bromides are rapidly absorbed and are excreted mainly in urine, and repeated doses tend to cause accumulation with a consequent replacement of chloride ion.  The use of bromide is stopped because of the possibility of bromism (bromide poisoning), the early sign of intoxication include insomnia, dizziness, weakness and headache.  Treatment of bromism by administration of sodium chloride (6 gm daily in divided doses) or ammonium chloride is used in whom sodium intake is to be limited. Lithium: It is readily absorbed from intestine, and accumulates in the body. the extent of its accumulation depends on sodium intake (decrease sodium intake accelerate lithium accumulation) and potentiate toxicity. Lithium intoxication is treated by withhold lithium and provide sodium intake.  Lithium is a depressant to the CNS and has a diuretic action.  Lithium carbonate is administered orally in manic depressive disorder.  Lithium carbonate can affect thyroid function causing myxedema( deficient thyroid function) and decrease protein bound iodine levels and increase iodine intake.  Lithium can cause diabetes incipidus (increase urination without glucosurea). Gold:  It is used in the rheumatoid arthritis, and therapeutic gold compounds are administered i.m. Orally is poorly absorb and irritant.  The gold is rapidly enters the plasma where it remains bound to albumin for several days so it is usually administered weekly.  Gold toxicity involves the skin, mucous membrane, joints, blood, kidney, liver and nervous system.  Treatment of toxicity involves cessation of administration, supportive treatment and dimercaprol can be used.  Lead: Its salts were used topically as astringent. Oral lead generally absorbed slowly and excreted reasonably well. Inorganic lead cannot pass through intact skin but it will absorbed through abraded skin, thus Lead solution used as astringent could be absorbed systemically while organic Lead such as tetraethyl Lead can penetrate skin rapidly. Once absorbed, the Lead can be found initially in the erythrocyte and soft tissue. Later the kidneys contain the most Lead with the liver,then over time redistribution occur to be found in bone, teeth and hair. Lead poisoning : While Lead may be considered a protein precipitant by combining with the cysteine sulfhydryl groups of protein, chronic Lead poisoning manifests itself by inhibition of heme synthesis.  The most serious Lead poisoning symptom is encephalopathy which is more common in children.  Renal damage. Treatment of lead poisoning: Treatment is based on the use of chelating agents to remove the accumulated Lead from erythrocyte and soft tissue. Dimercaprol and calcium disodium edetate are used initially followed by penicillamine for follow up treatment. Acute poisoning from oral ingestion can be treated by administrating sodium or magnesium sulphate to precipitate the Lead followed by gastric lavage. Once deposited in the bone, lead is considered nontoxic until it is mobilized again. Thus, even though the environmental source of lead is removed the possibility of lead poisoning persists due to the lead that is stored in the body. Mercury: Metallic mercury is relatively nontoxic as such since it's the mercurous Hg+ and the mercuric Hg+2 cations are toxic, in addition that mercury vapor is toxic. Poisoning by soluble inorganic mercury salts can be avoided while organic mercurial compounds are very toxic and are the cause of most reports of mercury poisoning. Toxic effects of mercury similar to that of Lead due to its combining with protein sulfhydryl groups  Once absorbed, the mercuric cation concentrates mostly in kidney, with less concentration in liver, blood, bone marrow, and other tissues..  Acute poisoning usually occurs by ingestion of soluble mercuric salts, vomiting and diarrhea may result with diuresis (suppression of tubular reabsorption) and kidney damage. Treatment of acute poisoning : 1. Gastric lavage. 2. using of reducing agent such as sodium formaldehyde sulfoxylate to reduce the mercuric cation forming less soluble mercurous salt. 3. using of chelating agents such as dimercaprol or pencillamine. Mercurial salts are used as :  diuretics  antiseptics  parasiticides  Fungicides Disadvantages of organic mercurial diuretics: 1. Poor absorption from GIT 2. Slow onset of action 3. Sever toxicity