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Biomedical subjects

A Amdisen

Publications and source records attributed to A Amdisen.

At least 37 records · Page 2Linked to original sources
PubMed1982

Lithium treatment regimen and renal water handling: the significance of dosage pattern and tablet type examined through comparison of results from two clinics with different treatment regimens.

For many year two Danish psychiatric hospitals having used different lithium treatment regimens. In one, slow-release tablets were given in two daily doses and, in the other conventional tablets were given in a single daily dose. In both hospitals many patients developed polyuria. Multiple regression analyses with sex, age, treatment duration, serum lithium concentration, and treatment regimen as predictor variables showed that the two treatment regimens did not affect the glomerular filtration rate or the proximal reabsorption differently, but that distal water reabsorption was significantly less affected and polyuria less pronounced in the patients given conventional tablets once daily than in those give slow-release tablets twice daily. The authors are divided among themselves as regards the implications of these findings.

Adult↗
PubMed1982

Lithium treatment and thyroid function. A survey of 237 patients in long-term lithium treatment.

In a cross-sectional study of 237 patients treated with lithium for more than six months, 10 patients had serum thyroid stimulating hormone (TSH) values above 35 mU/l and concomitantly low triiodothyronine (T3) and abnormally low serum thyroxine (T4). Eight patients had TSH values of 10.0-34.9 mU/l, while T3 and T4 were within or close to the normal ranges. Most of the patients had TSH values of 0.9-9.9 mU/l and normal or close to normal T3 and T4 values. Three male patients had TSH below 0.9 mU/l, but normal T3 and T4 values. A retrospective investigation three years later showed that all patients with TSH above 35 mU/l had clinically diagnosed overt hypothyroidism and treated accordingly with either replacement therapy with thyroxine or discontinuation of the lithium treatment. The thyroid parameters normalized spontaneously in 2 out of 3 patients who had their lithium treatment discontinued, while one still needed replacement therapy 1 1/2 years after withdrawal of lithium. Five patients had been put on replacement therapy before the cross-sectional study. The frequency of overt hypothyroidism thus indicated a prevalence about ten times as high as should be expected. An overrepresentation of women was found in the group with TSH values above 10 mU/l, whereas the group with TSH values of 0.9-10.0 mU/l showed no such sex predomination. The age distribution was equal in all groups. TSH appeared to be the most efficient parameter in revealing undetected hypothyroidism in the present investigation of patients in long-term lithium treatment.

Adult↗
PubMed1982

Plasma arginine-vasopressin, renal-concentrating ability and lithium excretion in a group of patients on long-term lithium treatment.

Plasma arginine-vasopressin (AVP) was measured before and after 24 h of a 26-hour renal concentration test in 47 patients treated with lithium for 6-180 months (mean 70 months). In 34 of the patients, plasma AVP was also measured before and after a 2- to 4-hour period of water loading, and in 31 of the patients, creatinine, 125iothalamate, 131I-hippuran and lithium clearances were measured. Plasma AVP values were compared to those obtained in 8 healthy controls. Baseline AVP levels were significantly higher in the lithium-treated patients than in healthy controls. During the period of water deprivation AVP values increased significantly and during oral water loading a significant decrease took place, AVP values still being significantly higher in the lithium-treated patients than in the healthy controls. During oral water loading a slight increase in lithium clearance as well as fractional lithium excretion was seen as compared to values obtained during the last 2 h of a renal concentration test. This study demonstrates that antidiuretic hormone production is neither blocked nor inhibited during lithium treatment. The hypothalamic system reacts on water deprivation as well as on water loading. This study supports the notion that the main lithium-induced renal affection is a vasopressin-resistant impairment of renal concentrating ability.

Adult↗
PubMed1982

Lithium and drug interactions.

The mutual enhancement of the side effects of muscular tremor and rigidity caused by lithium and neuroleptic drugs should be recognised. However, at present the 'case' for a neuroleptic-lithium interaction producing severe organic brain syndrome is arguably weak; in the absence of standardised sampling for monitoring lithium serum concentrations such reports may simply reflect 'pure' lithium intoxication rather than a drug interaction. Certainly it seems unwarranted in this connection to ascribe specific properties to haloperidol. A potentially high risk of interaction should be recognised between lithium and natriuretic diuretics, and other drugs and therapeutic measures affecting sodium balance. Such interactions may disturb stable treatment monitoring and give rise to the start of self-increasing lithium intoxication. The practical clinical importance of lithium interactions with neuromuscular blocking agents, phenytoin, carbamazepine, iodide salts and methyldopa is only weakly supported by the data available at this time. However, if simple prophylactic measures are available when such drugs are to be used in patients receiving lithium, for example temporary withdrawal of lithium, it may be prudent to take such steps.

Anti-Inflammatory Agents↗
PubMed1982

Bioavailability of lithium carbonate and lithium citrate: a comparison of two controlled-release preparations.

The pharmacokinetics of two marketed controlled-release lithium preparations, lithium carbonate ('Priadel') and lithium citrate ('Litarex'), were compared in 5 normal volunteers in a crossover design using identical doses (27.2 mmol lithium). Although the total bioavailability of the two preparations was similar, the peak serum lithium achieved was significantly lower with the lithium citrate than with the lithium carbonate preparation.

Adult↗
PubMed1981

Lithium treatment and kidney function. A follow-up study of 237 patients in long-term treatment.

Two years after a survey of the kidney function in 237 patients given long-term lithium treatment the patients were invited for reexamination. Of 184 patients who came for the reexamination 147 had continued lithium treatment; in 37 patients the treatment had been discontinued. The lithium-treated patients were compared with a group of 68 manic-depressive patients who were about to be given prophylactic lithium treatment but who had not yet started. Neither the patients who continued nor the patients who had discontinued lithium showed any deterioration of glomerular filtration rate as assessed through determination of the 24-h creatinine clearance and the serum creatinine concentration; mean values in the lithium-treated patients were the same as mean values in patients not yet given lithium. Impairment of renal water reabsorption, revealed by increased 24-h urine volume and decreased urine osmolality after DDAVP, had progressed in the patients who continued lithium treatment, and multiple regression analysis revealed the duration of treatment and the serum lithium level to be significant predictor variables. In the patients who had discontinued lithium the changes in renal water handling had decreased. The urine volume was the same as that found in the patients not yet given lithium; maximum urine osmolality had not become fully normalized. Side effects such as thirst, nycturia, tremor, diarrhoea, oedema, and weight gain were found with the same frequency at the second as at the first examination in the patients who had continued lithium. In the patients who had discontinued lithium they were infrequent or absent.

Adult↗
PubMed1981

Albumin and beta 2-microglobulin excretion in patients on long-term lithium treatment.

Albumin and beta 2-microglobulin excretions were studied in 85 unselected patients treated with lithium for more than 6 months. In 15 patients a lithium-induced impaired renal concentrating ability was found, 13 of these patients revealed a chronic interstitial nephropathy on renal biopsy. There was no significant increase in albumin excretion, and a markedly increased beta 2-microglobulin excretion was seen in only 1 patient. This study supports the hypothesis that the lithium-induced renal lesion in confirmed to the distal part of the nephron.

Adult↗
PubMed1980

Serum concentration and clinical supervision in monitoring of lithium treatment.

Lithium therapy has become generally accepted as one of the major regimens for the treatment of acute mania as well as for the prevention of relapse in recurrent bipolar mood disorders. It is one drug for which monitoring is understood to be crucial, since the drug (1) has broad interindividual variability in dose-response, (2) often has a very narrow intraindividual therapeutic concentration index, (3) has a broad interindividual distribution of sensitivity and tolerance, and (4) is extremely dependent on stable kidney function for its successful and safe use. Determination of serum lithium concentration is the most important monitoring technique. However, the need for standardized clinical procedure coupled with corresponding reference ranges remains to be satisfied. The 12 hr standardized serum lithium is seen as the answer to this need, and the specifics of and indications for the procedure and appropriate reference values are given. The therapeutic range is suggested to lie between 0.30 and 1.30 mmoles/liter, with 1.50 mmoles/liter representing the lower limit of risk for intoxication. The treatment of initial and intercurrent lithium intoxication, which can reach life-threatening proportions, is also described.

Affective Disorders, Psychotic↗
PubMed1980

Clinically significant side effects of lithium treatment. A survey of 237 patients in long-term treatment.

A group fo 237 patients in a long-term lithium treatment were questioned specifically about five side effects commonly associated with lithium treatment and unspecifically about "other" complaints. About one tenth of the patients did not complain of side effects, two thirds had one or two complaints, and one fourth had three or more. About one half of the patients complained of hand tremor, two thirds of increase thirst, one fifth of weight gain exceeding 10kg, one fifth of diarrhea, and one tenth of edema of legs or face. A few patients had other complaints. For each side effect we analysed whether its presence was significantly associated with such patient and treatment variables as sex, age, duration of the lithium treatment, 12-h serum lithium concentration, type of lithium preparation, and additional medication. Men complained of tremor significantly more often than women. Diarrhea was significantly less frequent in patients given additional treatment with antidepressants. Weight gain was associated with increased thirst and fluid output and with significantly increased blood pressure. None of the other variables distinguished between patients with and without the various complaints. We nevertheless hypothesize that a moderate reduction of the serum lithium level may lead to a lowering of the frequency of some side effects.

Adult↗
PubMed1979

Renal function and plasma aldosterone during acute lithium intoxication.

Studies on plasma aldosterone, total serum protein, electrolytes, osmolal concentrations in serum and urine, creatinine, lithium and osmolal clearances were carried out on 14 patients suffering from lithium intoxication. The determinations were done on samples obtained on admission and during the following twelve days of treatment with hemodialysis, sodium chloride loading, or forced diuresis. Plasma aldosterone and total serum protein were increased; serum sodium concentrations and creatinine clearances were decreased on admission. Serum osmolality was normal; urine osmolal concentration was just above that in plasma. The results showed that the lithium intoxicated patients were moderately depleted of sodium and water on admission. Plasma aldosterone, total serum protein and serum sodium were normalized during treatment. Creatinine clearance increased but did not normalize in all patients. Renal concentrating tests were performed in five patients three to four weeks after lithium intoxication. The renal concentrating ability was reduced in all. The elevated plasma aldosterone seen in lithium intoxication might have been a result of sodium and water depletion. It is suggested that impaired renal concentrating ability induced by lithium may make some patients more susceptible to conditions which can lead to sodium and water loss, and thereby to lithium intoxication.

Acute Disease↗
PubMed1979

Lithium treatment and kidney function. A survey of 237 patients in long-term treatment.

Kidney function has been examined in 237 patients who in the autumn of 1977 were in lithium treatment at the Psychiatric Hospital in Risskov, most of them as outpatients. The average age was 42 years. The patients had been given lithium treatment for 0.5-17 years, mean duration 5 years. The mean lithium dosage was 33 mmol/day and the mean 12-hour serum lithium concentration 0.85 mmol/l. Glomerular filtration rate was assessed through determination of 24-hour creatinine clearance and serum creatinine, in some cases iothalamate clearance. Water excretion was assessed through determination of 24-hour urine volume and in some cases urine osmolality after 26 hours of fluid deprivation. Creatinine clearances, serum creatinine concentrations, and urine volumes were subjected to multiple regression analysis with various clinically relevant predictor variables. Affection of glomerular filtration rate was only moderate and progressed slowly. The data indicate that the risk of renal insufficiency and terminal azotemia is remote even when lithium is given for many years. A large number of the patients had altered water excretion with polyuria or lowered urine concentrating ability or both. Due to the extra fluid loss these patients are apt to develop dehydration, and they may then be in danger of lithium poisoning. We hypothesize that lithium-induced changes of kidney function may become less frequent and less pronounced if patients are maintained at serum lithium levels somewhat lower than those employed in the group studied here. We recommend careful monitoring of serum lithium levels, regular control of kidney function, and extra caution when physical illness or additional drug treatment may lead to disturbance of fluid and electrolyte balance.

Adult↗
PubMed1979

Plasma neutral amino acids in mania and depression: variation during acute and prolonged treatment with L-tryptophan.

The free tryptophan and plasma neutral amino acids including kynurenine have been determined before treatment, after a single load, and during prolonged treatment with L-tryptophan on a bipolar manic-depressive patient who has shown resistance to current treatments. The data of the patient were compared with the data of healthy control subjects in order to evaluate the availability of tryptophan to the brain. A relative deficiency of tryptophan in the plasma, as measured by the ratio of tryptophan to those amino acids which compete with tryptophan during transport processes, was found in the patient. Further, the patient showed an increased area under curve of plasma tryptophan after a load, and an increase in the competing amino acids during the load compared to a decrease in the control subjects. During the treatment with L-tryptophan the competing amino acids increased in the plasma. The results suggest that the patient suffered from a dysfunction of the processes which mediate active transport of tryptophan and other large neutral amino acids into tissues including the brain.

Amino Acids↗
PubMed1979

Chronic interstitial nephropathy in patients on long-term lithium treatment.

One-hundred and ten patients treated with lithium for more than six months were studied in order to determine the prevalence of lithium induced nephropathy. Eighteen of 69 patients (26 per cent) who had been treated for more than two years presented a chronic interstitial nephropathy characterized by a marked decrease in renal concentrating ability with a disproportionate preservation of glomerular filtration rate. Histologically, increased amounts of fibrotic tissue in the medulla and the cortex were found together with tubular atrophy. In 40 per cent of the patients who underwent renal biopsy, cystic formations in the cortex were found. The impairment of renal concentrating ability could be related to the duration of lithium treatment and the degree of tubular damage correlated with the degree of impairment of renal concentrating ability. Lithium induced, chronic nephropathy is a rather common complication of long-term lithium treatment and reduces the patients capacity to regulate water and electrolyte metabolism. As water and electrolyte loss appears to precede the slowly progressing lithium intoxication, the main hazard of lithium induced nephropathy is lithium intoxication.

Adult↗