Efficacy of Levothyroxine Sodium Soft Gelatin Capsules in Thyroidectomized Patients Taking Proton Pump Inhibitors: An Open-Label Study

Background: Treatment with proton pump inhibitors (PPIs) and antacids affects the gastrointestinal absorption of levothyroxine sodium (LT4) tablets. Patients with hypothyroidism taking LT4 and PPIs or antacids, thus, require appropriate monitoring. The objective of this study was to determine whether a soft gelatin capsule of LT4 (Tirosint®) would obviate the effect of PPIs on LT4 absorption. The objective was achieved by assessing the effects of a switch from a conventional LT4 tablet form to the same dose as soft capsules in thyroidectomized patients on treatment with LT4 and PPIs. Methods: Patients with history of hypothyroidism due to total thyroidectomy on stable treatment with LT4 tablets, and with gastrointestinal disease treated with PPIs, were switched to a 12-week treatment with Tirosint at the same dose of the LT4 tablets, while maintaining treatment with PPIs. Serum thyrotropin (TSH) levels were the primary endpoint of the study. Secondary efficacy endpoints were: serum levels of free thyroxine (fT4), total thyroxine (TT4), free triiodothyronine (fT3), total triiodothyronine (TT3), creatine-phosphokinase (CPK), sex-hormone binding globulin, ferritin, angiotensin converting enzyme, and a lipid panel. Results: Forty-seven patients (36 females and 11 males, mean age 55.4 years) were enrolled and 45 of them completed the study (2 patients withdrew consent). During treatment with Tirosint, mean TSH levels demonstrated a statistically significant decrease (mean changes from baseline: -0.32 mIU/L at week 6 and -0.68 mIU/L at week 12) and concomitant increases in thyroid hormone (TH) levels from baseline to week 12, which were statistically significant for fT3 and TT3 (mean changes from baseline: 0.26 pmol/L and 0.10 nmol/L, respectively). Significant decreases of serum low-density lipoprotein, total cholesterol, and CPK levels were observed at week 12. No signs/symptoms arose during the study that could be specifically correlated to either hypo- or hyperthyroidism. Conclusions: In thyroidectomized patients taking PPIs and replacement LT4, a switch from conventional LT4 tablets to LT4 soft capsules at the same dose was associated with a significant decrease in TSH and increase in TH, indicating that LT4 absorption may be less affected by PPIs when given in the form of soft capsules. Clinical Trial Registration: NCT03094416.

Finasteride cream in hirsutism

OBJECTIVE

To determine, in a preliminary study, whether women with hirsutism attributable to various causes would benefit from treatment with finasteride cream.

METHODS

Finasteride cream (0.25%) and placebo cream were administered to eight women with various degrees of facial hirsutism. The two creams were used on opposite sides of the face in an area of excessive hair growth. The side chosen for the finasteride cream versus placebo was randomized and blinded. In a 1 cm2 area on each side of the face, hair counts were done every 2 months throughout the 6-month study period. Hair thickness was also measured.

RESULTS

Hair follicles respond to testosterone by the conversion of this androgen to dihydrotestosterone through the action of 5a-reductase. Finasteride partially blocks this enzyme. Because of the easy solubility of this medication through the skin, a cream applied to the area of hair growth would be expected to decrease hirsutism locally. After a 6-month period, mean hair counts decreased significantly from 27.5 to 15.5 (P<0.05) in the finasteride-treated sites but showed no significant change from baseline in the placebo-applied sites. Moreover, the mean thickness of the measured hairs (in hundredths of millimeters) was significantly different between the placebo and finasteride-treated sites (4.33 versus 3.11, respectively; P<0.001).

CONCLUSION

In this study of women with facial hirsutism, topically applied finasteride significantly decreased hair growth and thickness, and no adverse effects were noted.

Use of thyroid ultrasound volume in calculating radioactive iodine dose in hyperthyroidism

One hundred twenty-one patients treated with 131I had a thyroid ultrasound to measure thyroid volume precisely. This volume measurement was used to determine the radioactive iodine dose. The average size (+/-SEM) of the thyroid glands measured in this manner was 39.7 cm3 +/- 1.9 cc. A significant correlation was found in the estimated size of the gland by the endocrinologists and the ultrasound volume. Of the 121 patients, 89 patients had the same 131I microcurie per gram of tissue factor to determine the radioactive iodine dose. This group of patients was further evaluated in this study. The average 131I dose (+/-SEM) given was 13.2 mCi +/- 0.5 mCi. The average time until hypothyroidism was achieved 2.85 +/- 0.14 months. Ultrasound provides a safe and precise way to determine actual thyroid size when calculating 131I doses.

Flushing in the carcinoid syndrome and plasma kallikrein

To examine the role of kallikrein in the etiology of flushing in the carcinoid syndrome, chromogenic substrates specific for kallikrein were used to measure two isoenzymes of this substance. The plasma and glandular kallikrein levels were determined in 20 carcinoid patients and in 17 controls. Kallikrein levels were not significantly different between these two groups. Twelve carcinoid patients and six controls were given alcohol and the kallikrein activity was measured before and at 2, 5, and 10 minutes after alcohol ingestion; kallikrein activity did not change significantly. Kallikrein was absent from the primary tumors of seven patients with carcinoids. These studies, therefore, indicate that kallikrein with subsequent induction of bradykinin formation is not solely responsible for the flushing in the carcinoid syndrome.

Iodine-131 metaiodobenzylguanidine scintigraphy of carcinoid tumors

Iodine-131 metaiodobenzylguanidine ([131I]MIBG) is concentrated in pheochromocytomas and can be detected by external imaging. We administered [131I]MIBG to 23 patients with carcinoid tumors to determine if it would be useful in scanning patients with these tumors. The carcinoid tumors of 14 of the 23 patients (61%) were visualized. Iodine-131 MIBG was concentrated most avidly by tumors of midgut origin (ileum, cecum); it was concentrated less avidly by some tumors of foregut origin (pancreas, stomach); it was not significantly concentrated by other tumors of foregut origin (bronchus). We conclude that 131I is a useful imaging agent for carcinoid tumors.

The intravenous insulin tolerance test in type I diabetes

The intravenous insulin tolerance test (ITT) allows general assessment of insulin sensitivity by determining the fall in plasma glucose after injection of 0.1 unit/kg regular insulin. To evaluate the usefulness of this test diagnostically in distinguishing Type I from Type II diabetes, 24 patients with Type I diabetes (defined as early age of onset, ideal body weight or less at onset, and insulin dependence) underwent ITTs. Seven patients had normal glucose disposal rates (Ki greater than or equal to 2.5. Nine patients had Ki less than 2.5 but greater than 1.0. Eight patients had Ki less than 1.0. The slopes did not correlate with the control of the diabetes (as assessed by measurement of glycosylated hemoglobin), the presence or titer of anti-insulin antibodies, the duration of the diabetes, the age of onset, the presence of complications, or the current insulin dose. These results indicate that varying amounts of insulin resistance may be present in Type I diabetes and cannot necessarily be explained by poor control or the presence of insulin antibodies.

Genetic transmission of tumoral calcinosis: autosomal dominant with variable clinical expressivity

Tumoral calcinosis is a rare inherited metabolic disorder characterized by hyperphosphatemia, elevated serum 1,25-dihydroxyvitamin D levels and periarticular cystic and solid calcifications. Based on previous investigations, the inheritance of this disorder has been postulated to be autosomal recessive. This interpretation was based on finding clinically affected subjects in only single generations of kindreds. We investigated four generations of an affected kindred and found nine subjects with the disease. A unique dental lesion which is specific for this disorder and serves as a phenotypic marker was identified in two generations of the kindred. In all affected subjects, elevated serum 1,25-dihydroxyvitamin D levels were found, although each member did not have the classical clinical findings of tumoral calcinosis. The possibility that this disorder may be variably expressed and have multiple formes frustes has not been previously considered. Using the unique dental lesion as well as the classical clinical and biochemical abnormalities, we found that in this kindred, tumoral calcinosis is transmitted in an autosomal dominant mode, with variable clinical expressivity.