<PAGE>
 
                                                                    EXHIBIT 24.1
<PAGE>
 
                                                                 EXHIBIT 24.1(a)

                                 SYNETIC, INC.


                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele, Anthony Vuolo and James V. Manning and each of
them, each with full power to act without the other, his true and lawful
attorneys-in-fact and agents, each with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign the Annual Report on Form 10-K of Synetic, Inc. for the
fiscal year ended June 30, 1997 (the "Annual Report") and to sign any and all
amendments to the Annual Report, and to file the same, with all exhibits thereto
and all other documents in connection therewith, with the Securities and
Exchange Commission, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary to be done as fully to all intents and purposes as he might or could
do in person, hereby ratifying and confirming all that each of said attorneys-
in-fact and agents or any of them may lawfully do or cause to be done by virtue
hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 24th day of September, 1997.


                                                /s/ Mervyn L. Goldstein, M.D.
                                           -----------------------------------
                                           MERVYN L. GOLDSTEIN, M.D.
<PAGE>
 
                                                                 EXHIBIT 24.1(b)

                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele, Anthony Vuolo and James V. Manning and each of
them, each with full power to act without the other, his true and lawful
attorneys-in-fact and agents, each with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign the Annual Report on Form 10-K of Synetic, Inc. for the
fiscal year ended June 30, 1997 (the "Annual Report") and to sign any and all
amendments to the Annual Report, and to file the same, with all exhibits thereto
and all other documents in connection therewith, with the Securities and
Exchange Commission, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary to be done as fully to all intents and purposes as he might or could
do in person, hereby ratifying and confirming all that each of said attorneys-
in-fact and agents or any of them may lawfully do or cause to be done by virtue
hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 22nd day of September, 1997.


                                               /s/ Ray E. Hannah
                                           --------------------------
                                           RAY E. HANNAH
<PAGE>
 
                                                                 EXHIBIT 24.1(c)

                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele, Anthony Vuolo and James V. Manning and each of
them, each with full power to act without the other, his true and lawful
attorneys-in-fact and agents, each with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign the Annual Report on Form 10-K of Synetic, Inc. for the
fiscal year ended June 30, 1997 (the "Annual Report") and to sign any and all
amendments to the Annual Report, and to file the same, with all exhibits thereto
and all other documents in connection therewith, with the Securities and
Exchange Commission, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary to be done as fully to all intents and purposes as he might or could
do in person, hereby ratifying and confirming all that each of said attorneys-
in-fact and agents or any of them may lawfully do or cause to be done by virtue
hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 19th day of September, 1997.


                                               /s/ Roger H. Licht
                                           -----------------------------

                                         ROGER H. LICHT
<PAGE>
 
                                                                 EXHIBIT 24.1(d)

                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Anthony Vuolo and James V. Manning and each of them, each with full
power to act without the other, his true and lawful attorneys-in-fact and
agents, each with full power of substitution and resubstitution, for him and in
his name, place and stead, in any and all capacities, to sign the Annual Report
on Form 10-K of Synetic, Inc. for the fiscal year ended June 30, 1997 (the
"Annual Report") and to sign any and all amendments to the Annual Report, and to
file the same, with all exhibits thereto and all other documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done as fully to all intents
and purposes as he might or could do in person, hereby ratifying and confirming
all that each of said attorneys-in-fact and agents or any of them may lawfully
do or cause to be done by virtue hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 24th day of September, 1997.


                                               /s/ Charles A. Mele
                                           ----------------------------
                                           CHARLES A. MELE
<PAGE>
 
                                                                 EXHIBIT 24.1(e)

                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele, Anthony Vuolo and James V. Manning and each of
them, each with full power to act without the other, his true and lawful
attorneys-in-fact and agents, each with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign the Annual Report on Form 10-K of Synetic, Inc. for the
fiscal year ended June 30, 1997 (the "Annual Report") and to sign any and all
amendments to the Annual Report, and to file the same, with all exhibits thereto
and all other documents in connection therewith, with the Securities and
Exchange Commission, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary to be done as fully to all intents and purposes as he might or could
do in person, hereby ratifying and confirming all that each of said attorneys-
in-fact and agents or any of them may lawfully do or cause to be done by virtue
hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 19th day of September, 1997.


                                               /s/ Herman Sarkowsky
                                           ------------------------------
                                           HERMAN SARKOWSKY
<PAGE>
 
                                                                 EXHIBIT 24.1(f)
                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele, Anthony Vuolo and James V. Manning and each of
them, each with full power to act without the other, his true and lawful
attorneys-in-fact and agents, each with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to sign the Annual Report on Form 10-K of Synetic, Inc. for the
fiscal year ended June 30, 1997 (the "Annual Report") and to sign any and all
amendments to the Annual Report, and to file the same, with all exhibits thereto
and all other documents in connection therewith, with the Securities and
Exchange Commission, granting unto said attorneys-in-fact and agents full power
and authority to do and perform each and every act and thing requisite and
necessary to be done as fully to all intents and purposes as he might or could
do in person, hereby ratifying and confirming all that each of said attorneys-
in-fact and agents or any of them may lawfully do or cause to be done by virtue
hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 24th day of September, 1997.


                                               /s/ Martin J. Wygod
                                           ---------------------------
                                           MARTIN J. WYGOD
<PAGE>
 
                                                                 EXHIBIT 24.1(g)

                                 SYNETIC, INC.

                               POWER OF ATTORNEY



   KNOW ALL MEN BY THESE PRESENTS, that the undersigned does hereby constitute
and appoint Charles A. Mele and Anthony Vuolo and each of them, each with full
power to act without the other, his true and lawful attorneys-in-fact and
agents, each with full power of substitution and resubstitution, for him and in
his name, place and stead, in any and all capacities, to sign the Annual Report
on Form 10-K of Synetic, Inc. for the fiscal year ended June 30, 1997 (the
"Annual Report") and to sign any and all amendments to the Annual Report, and to
file the same, with all exhibits thereto and all other documents in connection
therewith, with the Securities and Exchange Commission, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done as fully to all intents
and purposes as he might or could do in person, hereby ratifying and confirming
all that said attorneys-in-fact and agents or any of them may lawfully do or
cause to be done by virtue hereof.


   IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as of
this 24th day of September, 1997.


                                               /s/ James V. Manning
                                           ------------------------------
                                           JAMES V. MANNING