Plasma protein level

Some dmgs are bound to plasma proteins in blood. Plasma protein levels in blood may be decreased in the elderly, but this is most often not clinically relevant since a drug s elimination increases when the free, unbound drug concentration is enhanced (Turnheim 1998). The plasma albumin level may however be markedly decreased in elderly suffering from malnutrition or severe disease. For those patients the concentration of the free unbound drug can reach toxic levels (Waiter-Sack and Klotz 1996). 

Heavy kava users have also been observed to lose weight and have low plasma protein levels and low platelet and lymphocyte counts. Pulmonary hypertension and shortness of breath have rarely occurred. Kava should be avoided in pregnant women and children, since the consequences of use are unknown. A recent cause for concern is an uncommon idiosyncratic fiver toxicity associated with kava use in some cases, this has been severe enough to warrant fiver transplantation. It is unclear whether kava alone is to blame, but the safety of this herb is under review. Several European countries, where this problem was first reported, have either suspended sales or are acting to make kava a prescription drug. 

In pregnancy, the total body fluid increases by 8 liters, of which 80% is extracellular water. The plasma volume increases by 40 to 50% (1.2 to 1.5 liters). Consequently, in pregnancy there is an increase in plasma volume, decrease in plasma protein levels, increase in total and extracellular water compartments, and increase in total body fat. These alterations may change the volume of distribution of most drugs. 

Phenolphthalein is thought to exert its effect by inhibiting the movement of water and sodium from the colon into the blood and by stimulating mucus secretion. If misused on a prolonged basis, a consequential loss of mucus may lower the plasma protein level. Caster oil is hydrolyzed to ricinoleic acid, the active cathartic. It has an onset of action of 2 to 6 h. 

The total plasma protein level has been found to be normal or raised (C3, F7, L6, PI). Payne found an increase in the a2- and y-globulins (PI). Creery and Neill found an increase in the a2- at the expense of the (1-globulin, with an occasional rise in the y-globulin (C3). Forfar et al. found a rise in the a2- and (1-globulin in two out of six cases (F7). 

Kang MJ, Lee DY, Joo WA, Kim CW. Plasma protein level changes in waste incineration workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. J Proteome Res 2005 4(4) 1248-1255. 

Rates of hepatic synthesis of many plasma proteins are affected by a patient s endocrine status. The effects of some steroid hormones on individual plasma protein levels are given in Table 20-5. The plasma protein levels characteristic of a specific disease may therefore be complicated by the steroid status of a patient and by an inflammatory acute phase reaction. The abnormal steroid status may be the result of an intrinsic hormonal disorder or of treatment with steroid hormones, as in inflammation. 

The most commonly submitted samples for direct trace element analysis are of whole blood, blood plasma, or serum. Plasma protein levels of the relevant carrier proteins transferrin (Fe), albumin (Zn), ceruloplasmin (Cu), and selenoprotein P (Se) can give useful additional information. 

In the absence of dehydration, a raised plasma albumin level is very rare. However, factors other than the protein intake per se can bring about an increase in the serum protein levels above normal averages, even in the presence of mild to moderate protein deficiency (S25). In one tropical community, raised plasma albumin levels in the face of protein deficiency have been reported. This elevation was not the result of dehydration, or of racial differences, but was associated with a high proportion of vegetable protein in the diet (S25). Thus, plasma protein levels may not be a reliable indicator for the detection of mild protein deficiency. 

The rates and routes of metabolism can vary with age and the lower rates and reduced routes of metabolism usually seen in the yoimg and the old can make them more susceptible to drug action. Differences in hormonal levels, in particular, can lead to differences in metabolism between sexes. Dietary and environmental factors such as the presence of alcohol and cigarette smoke can affect metabolism, as can certain disease conditions, e.g., liver disorders, diabetes. Such conditions can lead to decreased enzyme activity, altered hepatic blood flow, and changes in plasma protein levels which, in turn, can affect circulating active drug levels. 

Hermens, W.T., Willems, G.M. and Visser, M.P. (1982) Quantification of Circulating Proteins Theory and Applications Based on Analysis of Plasma Protein Levels, Martinus Nijhoff, The Hague. 

Plasma protein levels, LPO, GT levels, membrane stability, phagocytosis (haemolymph)... 

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