dihydropyridines and Joint-Diseases

Ankle oedema is a common adverse event during treatment with dihydropyridine (DHP) calcium channel antagonist therapy, the incidence of which is dose related. The three mechanisms put forward to explain the formation of oedema during calcium channel antagonist therapy are arteriolar vasodilation, impairment of the local vascular autoregulation of blood flow and impaired protection against hydrostatic load. The importance of differential arteriolar-venular dilation has been demonstrated in numerous clinical studies. In particular, differences in sympathetic overactivation after arterial vasodilation have been shown to be related to differences in ankle oedema rates. If these results are confirmed, calcium channel antagonists that activate the sympathetic nervous system to a lesser extent, such as manidipine, may become first-choice calcium channel antagonists because of their more favourable adverse event profile.

Topics: Ankle Joint; Arterioles; Calcium Channel Blockers; Dihydropyridines; Edema; Humans; Joint Diseases; Norepinephrine; Randomized Controlled Trials as Topic; Sympathetic Nervous System; Vasodilation

All studies suggesting a lower incidence of edema on lacidipine than on amlodipine are based on subjective scoring. Therefore, we have compared edema formation on two dihydropyridine calcium channel blockers, using an accurate method for quantitative assessment of foot volume. In a randomized study, we treated 62 patients with essential hypertension for 12 weeks starting with either lacidipine 4 mg o.d. (n = 30) or amlodipine 5 mg o.d. (n = 32). At 6 weeks, the doses were increased to that maximally allowed (lacidipine 6 mg, n = 18; amlodipine 10 mg, n = 12) if trough diastolic blood pressure response was insufficient (>90 mmHg and decrease < 10 mmHg). Edema, scored visually, occurred more frequently (p = 0.02) on amlodipine (15/32) than on lacidipine (6/30); this was confirmed by an increase of foot volume above the 95% upper limit of normal variation in 15 patients on amlodipine and in only five patients on lacidipine (p = 0.01). In the whole group of patients, both the increases of foot volume and the decreases of blood pressure just failed to be significantly different between amlodipine and ]acidipine (foot volume, +3.3+/-1.0% on amlodipine and +1.2+/-0.5% on lacidipine, p = 0.08; mean arterial pressure, -11+/-1% on amlodipine and -8+/-1% on lacidipine, p = 0.052). In patients requiring dose increase, the increase of foot volume on amlodipine was more pronounced (p < 0.05), and the antihypertensive effect was larger (p < 0.05) than on lacidipine. In conclusion, our data show a higher incidence of edema on amlodipine than on lacidipine, which has to be explained at least partly by a comparably higher dose c.q. a larger antihypertensive effect of amlodipine. Other mechanisms might have contributed to these differences and need to be explored.

Topics: Adolescent; Adult; Aged; Amlodipine; Ankle; Blood Pressure; Calcium Channel Blockers; Dihydropyridines; Edema; Female; Foot; Humans; Hypertension; Joint Diseases; Male; Middle Aged; Single-Blind Method

Platelet-activating factor (PAF) and its receptor (PAFR) have been shown to be involved in several inflammatory events, including neutrophil chemoattraction and nociception. The present study addressed the role of PAF in the genesis of articular hyperalgesia in a model of joint inflammation. Zymosan-induced articular hyperalgesia, oedema and neutrophil migration were dose-dependently reduced following pretreatment with selective PAFR antagonists, UK74505 (5, 10 and 20 mg/kg) and PCA4248 (3, 10, 30 mg/kg). These parameters were also reduced in PAF receptor-deficient mice (PAFR(-/-)). The hyperalgesic action of PAF was further confirmed by the demonstration that joint injection of PAF induces a dose- (0.3, 1 and 3 μg/joint), time- and PAFR-dependent articular hyperalgesia and oedema. The PAF hyperalgesic mechanisms were dependent on prostaglandins, leukotrienes and neutrophils, as PAF-induced articular hyperalgesia was inhibited by indomethacin (COX inhibitor), MK886 (leukotrienes synthesis inhibitor) or fucoidan (leukocyte rolling inhibitor). Furthermore, PAF-induced hyperalgesia was reduced in 5-lypoxigenase-null mice. In corroboration of these findings, intra-articular injection of PAF promotes the production of LTB(4) as well as the recruitment of neutrophils to the joint. These results suggest that PAF may participate in the cascade of events involved in the genesis of articular inflammatory hyperalgesia via stimulation of prostaglandins, leukotrienes and neutrophil migration. Finally, targeting PAF action (e.g., with a PAFR antagonist) might provide a useful therapeutic approach to inhibit articular inflammatory hyperalgesia.

Topics: Animals; Dihydropyridines; Disease Models, Animal; Dose-Response Relationship, Drug; Hyperalgesia; Imidazoles; Immune System Diseases; Inflammation; Joint Diseases; Leukocyte Disorders; Leukotriene B4; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Neutrophils; Platelet Activating Factor; Platelet Membrane Glycoproteins; Prostaglandins; Receptors, G-Protein-Coupled; Time Factors; Zymosan