Terrie Jo Chandler brought a medical malpractice suit against Ronald Koenig, M.D., Mark Kozinn, M.D., and The Atlanta Neurological Institute, P.C. Pursuant to OCGA § 9-11-9.1 (a), she submitted the affidavit of Jerry Buccafusco, Ph.D., Professor of Pharmacology and Toxicology at the Medical College of Georgia. All defendants raised as a defense the failure of Chandler to comply with OCGA § 9-*68511-9.1, and the trial court granted their motion to dismiss based on that defense. Chandler appeals.
OCGA § 9-11-9.1 (a) provides that “[i]n any action for damages alleging professional malpractice, the plaintiff shall be required to file with the complaint an affidavit of an expert competent to testify, which affidavit shall set forth specifically at least one negligent act or omission claimed to exist and the factual basis for each such claim.” The question in this appeal is who is “an expert competent to testify” for purposes of OCGA § 9-11-9.1 (a).
We hold that for an affiant to constitute “an expert competent to testify” under OCGA § 9-11-9.1 (a), the affiant’s expertise must include knowledge of the standard of care applicable to the defendant-physician as to at least one of the matters on which the plaintiff’s malpractice claim is based.. This holding is mandated by the language of the statute that the expert affidavit submitted by the plaintiff must specifically set forth “at least one negligent act or omission” allegedly committed by the defendant-physician. To support a claim of medical malpractice, any such “negligent act or omission” must have been the result of the defendant-physician’s breach of a duty owed the plaintiff-patient by failing to exercise the requisite degree of skill and care. Cherokee County Hosp. Auth. v. Beaver, 179 Ga. App. 200-201 (1) (345 SE2d 904) (1986). See McDaniel v. Hendrix, 260 Ga. 857, 859 (1) (401 SE2d 260) (1991). Since an affiant whose expertise does not encompass the standard of care applicable to the defendant-physician in the performance of one of the challenged acts or omissions does not possess the knowledge to opine whether malpractice existed in the defendant-physician’s performance, as alleged by the plaintiff, such an affiant would not qualify as an “expert competent to testify” under OCGA § 9-11-9.1 (a).
Our interpretation is consistent with opinions holding that the mere fact an affiant is an expert in his or her school of knowledge does not necessarily mean the expert is “competent to testify” under OCGA § 9-11-9.1 (a). See Piedmont Hosp. v. Milton, 189 Ga. App. 563 (377 SE2d 198) (1988) (rejecting a medical doctor’s affidavit against nursing personnel in part because it did not show that the medical doctor was an expert competent to testify “in the field of nursing”); Milligan v. Manno, 197 Ga. App. 171 (397 SE2d 713) (1990) (setting forth the general rule that a member of a school of practice other than that to which the defendant belongs is not competent to testify as an expert in a malpractice case). This result is also in accord with our opinion in 0-1 Doctors &c. Co. v. Moore, 190 Ga. App. 286 (378 SE2d 708) (1989), in which we interpreted OCGA § 9-11-9.1 to mean that when the affiant is “competent to testify,” there is no need to set forth in the affidavit the standard of care or the expert affiant’s familiarity with the standard of care to fulfill the re*686quirements of OCGA § 9-11-9.1 (a). 0-1 Doctors, supra at 287.
In Milligan, supra, this court discussed in the context of the OCGA § 9-11-9.1 affidavit the general rule excluding practitioners of one school of medicine from testifying against members of other schools and the exception to that rule, as set forth in Sandford v. Howard, 161 Ga. App. 495, 497 (5) (288 SE2d 739) (1982), that “ ‘[w]here there is proof by competent evidence that the methods of treatment are the same despite the difference in the nomenclature of the schools involved, the witness is competent to testify.’ [Cit.]” The Milligan court then applied that exception to the affidavit required by OCGA § 9-11-9.1 and held that where the affidavit “establishes that the witness is a member of a different school of medicine than that practiced by the defendant but contains no evidence that the methods of treatment of plaintiff’s condition are the same so as to bring the witness within the exception to the general rule that he is incompetent to testify[, then] the affidavit is legally insufficient.” Id. at 172. We find no conflict between Milligan and our holding in 0-1 Doctors &c., supra, because 0-1 Doctors &c. is distinguishable on the basis that it involved an expert affiant who was a member of the same school of medicine as that practiced by the defendant-physicians.
The general rule and its exception, as discussed in Milligan, supra, are addressed to and have been applied only in cases involving expert witnesses in health care professions who treat patients.1 Likewise, McCormick v. Avret, 154 Ga. App. 178, 179 (267 SE2d 759) (1980), cited by the dissent, involved testimony by one health care professional (a licensed nurse) against another (a medical doctor), and thus is consistent with (though not referencing) the general rule and its exception. In the case sub judice, it is uncontroverted that appellant’s expert, Dr. Buccafusco, is a pharmacologist, not a licensed practitioner of any school of medicine or a licensed practitioner of any related field, such as pharmacy. However, we need not here determine whether affiants such as Dr. Buccafusco who are not licensed professionals in the health care field are competent to testify to the standard of care of defendants who are practicing licensed health care professionals, because even assuming, arguendo, that a pharmacologist can derive from education and training the knowledge sufficient to render him an expert on the standard of care required of a medical doctor, the facts as set forth in the affidavit of appellant’s expert are insufficient to establish his expertise on this subject.
*687In his affidavit Dr. Buccafusco set forth his fields of specialty, the scientific and professional societies to which he is a member, and averred that he trains medical students and postgraduates in regard to the properties and interactions of drugs as part of his duties as a professor of pharmacology at MCG. Dr. Buccafusco also opined that he was “familiar [with the] standard of care required and the properties and interactions of the drugs prescribed to [appellee] by [appellants] and with their recommended use” and was “competent to testify regarding the standards of care and recommended use” of those drugs. However, “ [competency as an expert is not demonstrated by mere familiarity. During the course of one’s education, training, or experience as a [pharmacologist], it is possible to become ‘familiar’ with the standard of care and treatment generally employed by [medical doctors]. Such familiarity would not, however, qualify one as an expert in that regard. An expert witness is one who through education, training, or experience has peculiar knowledge concerning some matter of science or skill to which his testimony relates. Absent some evidence to show that the affiant’s education, training, or experience as a [pharmacologist] would likewise demonstrate his similar expert qualifications as to [the prescribing of drugs by a medical doctor], the ‘exception’ in [Milligan, supra] would not be shown.” (Citations and punctuation omitted.) Bethea v. Smith, 176 Ga. App. 467, 469 (336 SE2d 295) (1985).
Dr. Buccafusco’s affidavit establishes that he is an internationally recognized pharmacologist and possesses expertise in that area which probably far exceeds that of the average medical doctor. However, other than Dr. Buccafusco’s bare assertion that he is familiar with the applicable standard of care, nothing in Dr. Buccafusco’s affidavit explains how his pharmacological education or his professorial duties has provided him with expert knowledge of the standard of care in the prescribing of drugs ordinarily employed throughout the general medical profession by physicians who are years removed from the intensive pharmacological training they received in medical school and for whom the prescribing of drugs is but one facet of their practice. Bethea, supra. Because there is no showing of a professional overlap of expertise in at least' one matter alleged by appellant to constitute malpractice, compare McCormick, supra at 179, Dr. Buccafusco could not come within the exception to the general rule that he is incompetent to testify. Milligan, supra at 172. Therefore, appellant’s affidavit did not meet the requirement of OCGA § 9-11-9.1 (a), and the trial court did not err by granting appellees’ motion to dismiss.
Judgment affirmed.
McMurray, P. J., Birdsong, P. J., Carley, P. J., and Johnson, J., concur. Pope, Beasley, Cooper and Andrews, JJ., dissent.E.g:, Milligan, supra (affidavit by osteopathic physician submitted in suit against allopathic physician); Hicks v. Mauldin, 190 Ga. App. 660, 661-662 (4) (379 SE2d 806) (1989) (osteopathic pediatrician testified against allopathic general practitioner); Bethea v. Smith, 176 Ga. App. 467, 468-470 (2) (336 SE2d 295) (1985) (affidavit by podiatrist against orthopedic surgeon); Sandford, supra (orthopedist’s testimony against podiatrist).