- Email: [email protected]
Reply: A comment on “Kavanagh M, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis”
EBLUEPRINTS
A comment on ‘‘Kavanagh M, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis’’ To the Editor: Kavanagh, Oh, and Shams1carried out research to investigate the effect of botulinum toxin type A delivered by iontophoresis on patients with primary hyperhidrosis in 2004. In order for a drug to be delivered by iontophoresis, a device consisting of direct current, an active (drug delivery), and a reference electrode is required.2 In their study, an anode was selected as the active electrode. In 2006, they performed a survey to verify their previous results in which they amazingly used a cathode as the active electrode.3 According to the 2004 study, using an anode as the active drug delivery electrode was expected. Although the authors referred to their previous study, they used cathode as the active drug delivery electrode without mentioning any reason for their choice. Methodologically, the latter study was against the previous one since the active drug delivery electrode that has the most important role in transferring drug into the body was totally different in these studies, whereas the results showed a significant decrease in both surveys. It is apparent that one of these studies is undoubtedly wrong because it is not possible for a drug to be delivered by both cathode and anode electrodes. Sanaz Devarian, MSc, PT Department of Physiotherapy, Faculty of Rehabilitation, Medical University of Shaheed Beheshti, Tehran, Iran Funding sources: None. Conflicts of interest: None declared. Correspondence to: Sanaz Davarian, MSc, PT, Department of Physiotherapy, Faculty of Rehabilitation, Medical University of Shaheed Beheshti, Damavand Ave. across from Bo-Ali Hospital, 16169 Tehran, Iran E-mail: [email protected] REFERENCES 1. Kavanagh GM, Oh C, Shams K. BOTOX delivery by iontophoresis. Br J Dermatol 2004;151:1093-5. 2. Costello CT, Jeske AH. Iontophoresis: application in transdermal medication delivery. Phys Ther 1995;75:554-63.
J AM ACAD DERMATOL
3. Kavangh GM, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis. J Am Acad Dermatol 2006;55(Suppl):S115-7. doi:10.1016/j.jaad.2007.08.040
Reply To the Editor: Ms Davarian draws our attention to an apparent inconsistency of methodology in our two Botox delivery experiments using iontophoresis. Our language about cathodes and anodes was ambiguous, but there was no change in our methodology. ‘‘Cathode’’ means the pole that releases electrons; ‘‘anode’’ means the pole to which they move. Electron flow and current not being the same thing—here they work in opposite directions--one can think of our negatively charged drug reservoir as the drug-delivery cathode (which is the language we used in our JAAD article1) and at the same time the electron-flow anode (which word, confusingly, we did use in the British Journal of Dermatology2). In any case, in both of our studies we always attached the black, negative cable to the drug reservoir. Our methodology in both studies was therefore identical (hence the consistency of our results). Gina M. Kavanagh, MRCP (Eire),a and Kave Shams, BSc(Hons), MB ChB(Edin)b Department of Dermatology, Royal Infirmary of Edinburgh,a and the College of Medicine and Veterinary Sciences, University of Edinburgh,b Edinburgh, Scotland Funding sources: None. Conflict of interest: None declared. Correspondence to: Gina M. Kavanagh, MRCP (Eire), Department of Dermatology, Royal Infirmary of Edinburgh, Lauriston Building, Lauriston Place, Edinburgh EH3 9YW, Scotland REFERENCES 1. Kavanagh GM, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis. J Am Acad Dermatol 2006; 55:S115-7. 2. Kavanagh GM, Oh C, Shams K. BOTOX delivery by iontophoresis. Br J Dermatol 2004;151:1093-5. doi:10.1016/j.jaad.2007.07.049
APRIL 2008 e1
A comment on ‘‘Kavanagh M, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis’’ To the Editor: Kavanagh, Oh, and Shams1carried out research to investigate the effect of botulinum toxin type A delivered by iontophoresis on patients with primary hyperhidrosis in 2004. In order for a drug to be delivered by iontophoresis, a device consisting of direct current, an active (drug delivery), and a reference electrode is required.2 In their study, an anode was selected as the active electrode. In 2006, they performed a survey to verify their previous results in which they amazingly used a cathode as the active electrode.3 According to the 2004 study, using an anode as the active drug delivery electrode was expected. Although the authors referred to their previous study, they used cathode as the active drug delivery electrode without mentioning any reason for their choice. Methodologically, the latter study was against the previous one since the active drug delivery electrode that has the most important role in transferring drug into the body was totally different in these studies, whereas the results showed a significant decrease in both surveys. It is apparent that one of these studies is undoubtedly wrong because it is not possible for a drug to be delivered by both cathode and anode electrodes. Sanaz Devarian, MSc, PT Department of Physiotherapy, Faculty of Rehabilitation, Medical University of Shaheed Beheshti, Tehran, Iran Funding sources: None. Conflicts of interest: None declared. Correspondence to: Sanaz Davarian, MSc, PT, Department of Physiotherapy, Faculty of Rehabilitation, Medical University of Shaheed Beheshti, Damavand Ave. across from Bo-Ali Hospital, 16169 Tehran, Iran E-mail: [email protected] REFERENCES 1. Kavanagh GM, Oh C, Shams K. BOTOX delivery by iontophoresis. Br J Dermatol 2004;151:1093-5. 2. Costello CT, Jeske AH. Iontophoresis: application in transdermal medication delivery. Phys Ther 1995;75:554-63.
J AM ACAD DERMATOL
3. Kavangh GM, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis. J Am Acad Dermatol 2006;55(Suppl):S115-7. doi:10.1016/j.jaad.2007.08.040
Reply To the Editor: Ms Davarian draws our attention to an apparent inconsistency of methodology in our two Botox delivery experiments using iontophoresis. Our language about cathodes and anodes was ambiguous, but there was no change in our methodology. ‘‘Cathode’’ means the pole that releases electrons; ‘‘anode’’ means the pole to which they move. Electron flow and current not being the same thing—here they work in opposite directions--one can think of our negatively charged drug reservoir as the drug-delivery cathode (which is the language we used in our JAAD article1) and at the same time the electron-flow anode (which word, confusingly, we did use in the British Journal of Dermatology2). In any case, in both of our studies we always attached the black, negative cable to the drug reservoir. Our methodology in both studies was therefore identical (hence the consistency of our results). Gina M. Kavanagh, MRCP (Eire),a and Kave Shams, BSc(Hons), MB ChB(Edin)b Department of Dermatology, Royal Infirmary of Edinburgh,a and the College of Medicine and Veterinary Sciences, University of Edinburgh,b Edinburgh, Scotland Funding sources: None. Conflict of interest: None declared. Correspondence to: Gina M. Kavanagh, MRCP (Eire), Department of Dermatology, Royal Infirmary of Edinburgh, Lauriston Building, Lauriston Place, Edinburgh EH3 9YW, Scotland REFERENCES 1. Kavanagh GM, Shams K. Botulinum toxin type A by iontophoresis for primary palmar hyperhidrosis. J Am Acad Dermatol 2006; 55:S115-7. 2. Kavanagh GM, Oh C, Shams K. BOTOX delivery by iontophoresis. Br J Dermatol 2004;151:1093-5. doi:10.1016/j.jaad.2007.07.049
APRIL 2008 e1