China
Africa
Explore chapters and articles related to this topic
Dopaminergic Prodrugs
Published in M.D. Francesco Amenta, Peripheral Dopamine Pathophysiology, 2019
Cesare Casagrande, Francesco Santangelo
The experimental approach to the development of ibopamine was directly related to the consideration of the usefulness of the continuous infusion of DA in the treatment of heart failure and of circulatory shock through the possibility of modulating the pharmacological response by an accurate titration of the rate of infusion37,38 in a range from 1 to 20 μg/kg/min. At the lowest rates, DA1 and DA2 receptors are activated; these mediate vasodilation by a direct vascular effect or by ganglionic and postganglionic sympathetic inhibition. By increasing the rate, cardiac contractility is increased by the stimulation of β-receptors. At still higher rates α-receptors are activated and BP is increased. In our laboratory, an anesthetized dog model with electromagnetic flowmeters on the ascending aorta and left renal artery and catheters in the left ventricle and femoral artery was established and it was shown to reproduce, in the same range of doses, the main hemodynamic modifications observed in patients.39,40
Non-adrenergic Non-cholinergic Autonomic Transmission
Published in Kenneth J. Broadley, Autonomic Pharmacology, 2017
Dopaminergic prodrugs have been developed to improve the delivery of the agent to its site of action and to achieve greater duration of action for chronic use in congestive heart failure (Rajfer & Davis 1990). This approach has utilized the catecholamine starting point of dopamine, which itself is poorly absorbed due to first-pass metabolism by COMT in the liver (Chapter 2). Retaining the dopamine moiety has advantages for dopaminergic activity, since it has limited access to the brain which avoids unwanted central side-effects. An example is ibopamine (Figure 12.5), which has been shown to be of benefit in clinical trials to many thousands of patients with congestive heart failure. Ibopamine is almost completely absorbed and is then rapidly hydrolysed by plasma esterases to yield the active drug, epinine, the free levels of which peak at ~1 hr after administration. The duration of action is 5–6 hr. Epinine shares the actions of dopamine (Table 4.1, Chapter 4) but is generally more potent at D2 receptors and β-adrenoceptors and has less indirect sympathomimetic activity. Whether it is more potent at D1 receptors than dopamine is less certain (van Woerkens et al. 1992). The beneficial effect in congestive heart failure may therefore be attributed to cardiac β-adrenoceptor stimulation and the reduced after-load from vasodilatation, and an improved renal function (see also Chapter 4). Additionally, D2 receptor activation lowers plasma noradrenaline levels by reducing its release from sympathetic nerve endings. The sustained reduction of sympathetic nerve activity may have a favourable effect on the prognosis of heart failure patients in who excessive sympathetic activity may be a risk factor for their death (Rajfer & Davis 1990).
Severe Hypotony Maculopathy in Anterior Uveitis Associated with Hodgkin Lymphoma
Published in Ocular Immunology and Inflammation, 2021
Alessandro Marchese, Chiara Giuffrè, Elisabetta Miserocchi, Maria Vittoria Cicinelli, Francesco Bandello, Giulio Modorati
Topical and local corticosteroids may be curative in acute settings, although adjunctive therapies are often required in chronic hypotony, including systemic and intravitreal steroids, topical ibopamine, intraocular injection of viscoelastic material, vitrectomy with cyclitic membranes removal, and intravitreal filling with silicone oil. Among medical therapies available today, topical ibopamine 2% (3,4 dyisobutyrrilester of N-methyldopamine), a synthetic sympathomimetic drug which is hydrolyzed to epinine (N-methyldopamine) by the aqueous humor esterase, has been used with success in eyes with hypotony secondary to different etiologies.19–21 Of note, our patient responded promptly to topical ibopamine 2%, with the restoration of macular anatomy in about 30 days of treatment.
Drug-induced Uveitis in HIV Patients with Ocular Opportunistic Infections
Published in Ocular Immunology and Inflammation, 2020
Ilaria Testi, Aniruddha Agarwal, Rupesh Agrawal, Sarakshi Mahajan, Alessandro Marchese, Elisabetta Miserocchi, Vishali Gupta
Treatment of cidofovir-induced uveitis does not necessarily imply discontinuation of antiviral therapy. Topical corticosteroids and cycloplegic/mydriatic agents are effective in controlling the inflammation in almost all patients. However, a majority of the patients have a chronic relapsing course of inflammation exacerbated by subsequent cidofovir infusions. In case of severe uncontrolled uveitis or persistent marked hypotony, cidofovir should be discontinued in favor of alternative antiviral medications. Accorinti et al. reported two cases of cidofovir-induced hypotony unresponsive to conventional medical therapy successfully treated with ibopamine 2% eyedrops.32 Ibopamine is believed to increase IOP by acting on the damaged ciliary epithelium through the stimulation of cell receptors, leading to an increase in aqueous humor production. However, continuous administration of ibopamine is needed to maintain stable levels of IOP.32
Intraocular Lymphoma
Published in Ocular Immunology and Inflammation, 2021
Emmett T. Cunningham, Elisabetta Miserocchi, Justine R. Smith, John A. Gonzales, Manfred Zierhut
Marchese et al.21 described a 44-year-old woman with chronic low-grade fever who presented to their tertiary referral clinic in Milan, Italy with bilateral granulomatous anterior uveitis, low IOP, and hypotony maculopathy. The inflammation improved in response to systemic and topical corticosteroids, whereas the IOP slowly normalized with the addition of topical 2% ibopamine administered six times daily. Diagnostic biopsy of an enlarged cervical lymph node lead to the diagnosis of Hodgkin lymphoma. The authors noted how uncommon it is for Hodgkin lymphoma to metastasize to the eye and reminded us of the utility of topical ibopamine for the treatment of ocular hypotony.