Predisposing factors of rhinitis medicamentosa: what can influence drug discontinuation?

BACKGROUND

the primary end point of our study was to define risk factors and identify the underlying conditions that may have led to the abuse of vasoconstrictors in rhinitis medicamentosa. Moreover, we analysed factors that may influence the vasoconstrictors discontinuation.

METHODOLOGY

this was a prospective case-control observational study. Cases and controls were evaluated at the baseline in order define factors that may have influenced onset of rhinitis medicamentosa. They were re-evaluated at 3 months to verify symptoms control and drug discontinuation. Finally, they underwent a phone call questionnaire after 12 months regarding drug discontinuation. A potential bias of our study is that evaluating discontinuation we included subjects treated differently according to the main diagnosis.

RESULTS

patients with rhinitis medicamentosa were more frequently smokers than controls, they had higher mean HAMA scores and positive psychiatric diseases history. Additionally, we frequently detected a local inflammation at nasal cytology in patients with rhinitis medicamentosa. A significant improvement in all nasal symptoms scores was observed in cases and controls but 29.4% of cases did not discontinue the vasoconstrictors. Two major factors negatively influenced discontinuation: positive nasal cytology and pathological HAMA score.

CONCLUSION

we observed that positive local inflammation, anxiety and smoking habit correlate positively with vasoconstrictors abuse. In addition, we demonstrated that anxiety and local inflammation were the most important factors impairing drug discontinuation.

[Effect of acute intravenous administration of thyroliberin on circulating reverse-T3]

Some of the Authors previously demonstrated a significant precocious serum T3 increase after 200 micrograms TRH acute intravenous administration (TRH test). Reverse-T3 (rT3) is now known to interfere with T4 conversion to T3. We therefore compared spontaneously occurring to TRH test-induced changes in T3 and rT3 serum levels within a group of four healthy women in fertile age. Maximum rT3 increase during TRH test did not differ significantly from the maximum spontaneous variation at the same time of the day. Maximum T3 increase, on the contrary, was significantly higher than observed maximum spontaneous variation (0,81 ng/ml versus 0,39 ng/ml increase, p less than 0,01). Possible implications are discussed in the text.

[Relationship between benign breast cancer and plasma levels of prolactin]

Prolactin (PRL) plasma levels were measured in the follicular phase of the cycle in 75 normally menstruating women divided into three groups: group I was normal (n. = 39), group II showed benign breast disease (n. = 26), group III hyperandrogenism (n. = 10). PRL levels were higher (670,8 +/- 61,2 microunits/ml) in the second group than in the first (216,0 +/- 12,0 microunits/ml; p less than 0,001) and in the third group (426,0 +/- 75,2 microunits/ml; p less than 0,02). Two mechanisms are hypothesized as a possible explanation for the results: a) hyperprolactinemia primarily alters progesterone/oestradiol ratio which secondarily initiates benign breast disease, or b) relative hyperestrogenism causes an increase in PRL plasma levels, which, in turn, interact with oestradiol to give mammary gland hypertrophy. Further studies are needed in order to elucidate the problem.

[Changes in blood prolactin in relation to the menstrual cycle]

Scientists are in general agreement on the hypothesis of a prolactin surge at midcycle. In order to test this hypothesis the Authors measured radioimmunoassayable circulating prolactin in the follicular phase and at midcycle in 15 normally menstruating health women. Due to the well known individual variability, mean prolactin values showed statistically poor differences in the two phases of the cycle. Though, a very good positive correlation (r = 0.72, p less than 0.01) was shown when individual follicular values were plotted against the corresponding midcycle values. The Authors conclude that at midcycle prolactin increases significantly and discuss physiological significance of this phenomenon.

[Preliminary observations on the existing relationship between plasma levels of prolactin and hypophyseal reserves of FSH and LH in the male]

PRL plasma levels and FSH and LH pituitary reserve were tested in ten apparently healthy male subjects. A good correlation was found between PRL on one hand and FSH plasma levels (p less than 0,05), LH plasma levels (p less than 0,01) and FSH pituitary reserve (p less than 0,01) on the other hand. This seems to support the current hypothesis that prolactin may cause a progressive clinically latent impairment in the spermatogenetic function of the testis. Further evidence is needed.

[Relation between the blood potassium and blood glucose responses and electrocardiographic changes, specifically the T wave, during the oral glucose tolerance test]

As previously showed by the Authors, serum K+ levels significantly decrease during OGTT. Moreover, two possible patterns were separated: a) monophasic decrease ("M" type curve) causing a mild but continuous down-slope, possibly physiologically more relevant, and b) polyphasic decrease ("O" type curve) causing a sharp down-slope followed by a rebound to normal K+ levels. In 10 of 12 M type subjects (83%) electrocardiographic changes were shown after OGTT, comparative to only 9 out of 16 O type subjects. The Authors believe this to be suggestive of a heavier impact of kaliemic changes on to myocardial function in M type curves. The hypothesis needs further analysis.

[Correlation between blood insulin response and blood potassium changes during oral glucose load (preliminary note)]

Glucose, insulin, K+ and Na+ serum levels were measured at fixed intervals during OGTT. Na+ showed no significant changes, while K+ progressively decreased from 0 to 240 min. A good correlation was found between kaliaemic lowest levels and insulin peak (p less than 0,01): the former followed the latter by 60-120 min. No correlation seemed to exist between nadir K+/basal K+ ratio and insulin peak. The results and their clinical implications are discussed.

Renal-portal shunt to restore normal reninism and blood pressure in experimental renovascular hypertension in dogs

The role of the liver in the metabolism of renin was evaluated in dogs with high plasma renin and hypertension due to experimental bilateral renal artery stenosis. Ten adult dogs were studied in three consecutive phases: (1) basal conditions, (2) with bilateral ischemic kidneys, and (3) after derivation of renal vein blood into the portal system. Secretion, total clearance, hepatic clearance, and hapatic extraction of renin were estimated in each phase by measuring plasma renin activity (PRA) in blood collected simultaneously from arteries, inferior vena cava, vena porta, hepatic and renal veins, and by determining renal and hepatic blood flow. Blood pressure was measured by intra-arterial catheterization. The results demonstrated an increase in the hepatic metabolism of renin when the hyper-reninemic patterns of renal blood directly perfused the liver. Under these conditions, hepatic and circulating renin fell to basal values and blood pressure returned to normal.